Subject: draft-ietf-trunkmib-ds1-mib-08.txt

From: Dave Fowler <[email-masked]>
Date: Sun, 15 Feb 1998 16:12:14 -0500

Hi.

Will you please post the enclosed as an internet draft.  For the
information of the 
trunk mib working group, the following changes were made:

Explanaory Text:

Added an ifStackTable example for DS1 on Ds2 
Added description of channelization and examples of how to use it
Explicitly state that J2 is not supported
Stated that performance parameters continue to be collected when the
interface is down
Updated some references to newer versions.
Completed the security section to discuss the disposition of every
read-write object

MIB:
linetypes for ds2 and e2 were added
dsx1CircuitIdentifier is no longer deprecated
linecoding of B6ZS was added for DS2
changed dsx1Ds1Number to dsx1Ds1ChannelNumber
Changed dsx1Channelization to allow indication of os ds2 channelized
into ds1 as
well as ds1 channelizad into ds0
Changed channelization to read-write
Added dsx1ChannelMapping table and made it mandatory for the case when
ds3 is channelized into ds1s
Created MIN-ACCESS of read-only for all read-write objects 

-- 
David Fowler                                   email:
[email-masked]
Newbridge Networks Corporation                 voice: (613) 599-3600 
ext.6559
600 March Rd, Kanata, Ontario, Canada K2K 2E6  fax:   (613) 599-3619

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                     Definitions of Managed Objects
              for the DS1, E1, DS2 and E2 Interface Types

                      Wed Feb 11 19:26:27 EST 1998

                   draft-ietf-trunkmib-ds1-mib-08.txt

                         David Fowler (editor)
                           Newbridge Networks
                          [email-masked]

Status of this Memo

   This document is an Internet-Draft.  Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups. Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as ``work in progress.''

   To learn the current status of any Internet-Draft, please check the
   ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow
   Directories on ds.internic.net (US East Coast), nic.nordu.net
   (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific
   Rim).

Abstract

   This memo defines an experimental portion of the Management
   Information Base (MIB) for use with network management protocols in
   the Internet community.  In particular, it describes objects used for
   managing DS1, E1, DS2 and E2 interfaces.  This document is a
   companion document with Definitions of Managed Objects for the DS0,
   DS3/E3 and SONET/SDH Interface Types, rfcTBD [19], rfcTBD [17] and
   rfcTBD [18].

   This memo specifies a MIB module in a manner that is both compliant
   to the SNMPv2 SMI, and semantically identical to the peer SNMPv1
   definitions.

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   This memo does not specify a standard for the Internet community.

   This document entirely replaces RFC 1406.

1.  The SNMPv2 Network Management Framework

   The SNMP Network Management Framework presently consists of three
   major components.  They are:

   o    the SMI, described in RFC 1902 [1] - the mechanisms used for
        describing and naming objects for the purpose of management.

   o    the MIB-II, STD 17, RFC 1213 [2] - the core set of managed
        objects for the Internet suite of protocols.

   o    the protocol, RFC 1157 [3] and/or RFC 1905 [4], - the protocol
        for accessing managed objects.

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

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2.  Object Definitions

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1)
   defined in the SMI.  In particular, each object type is named by an
   OBJECT IDENTIFIER, an administratively assigned name.  The object
   type together with an object instance serves to uniquely identify a
   specific instantiation of the object.  For human convenience, we
   often use a textual string, termed the descriptor, to also refer to
   the object type.

2.1.  Changes from RFC1406

   The changes from RFC1406 are the following:

        (1)  The Fractional Table has been deprecated.

        (2)  This document uses SNMPv2 SMI.

        (3)  Usage is given for ifTable and ifXTable.

        (4)  Example usage of ifStackTable is included.

        (5)  dsx1IfIndex has been deprecated.

        (6)  Support for DS2 and E2 have been added.

        (7)  Additional lineTypes for DS2, E2, and unframed E1
             were added.

        (8)  The definition of valid intervals has been clarified
             for the case where the agent proxied for other
             devices.  In particular, the treatment of missing
             intervals has been clarified.

        (9)  An inward loopback has been added.

        (10) Additional lineStatus bits have been added for Near End
             in Unavailable Signal State, Carrier Equipment Out of
             Service, DS2 Payload AIS, and DS2 Performance Threshold.

        (11) A read-write line Length object has been added.

        (12) Signal mode of other has been added.

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        (13) Added a lineStatus last change, trap and enabler.

        (14) The e1(19) ifType has been obsoleted so this MIB
             does not list it as a supported ifType.

        (15) Textual Conventions for statistics objects have
             been used.

        (16) A new object, dsx1LoopbackStatus has been introduced
             to reflect the loopbacks established on a DS1 interface
             and the source to the requests.  dsx1LoopbackConfig
             continues to be the desired loopback state while
             dsx1LoopbackStatus reflects the actual state.

        (17) A dual loopback has been added to allow the setting of
             an inward loopback and a line loopback at the same time.

        (18) An object indicating which channel to use within a
             parent object (i.e. DS3) has been added.

        (19) An object has been added to indicate whether or not
             this DS1/E1 is channelized.

        (20) Line coding type of B6ZS has been added for DS2

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3.  Overview

   These objects are used when the particular media being used to
   realize an interface is a DS1/E1/DS2/E2 interface.  At present, this
   applies to these values of the ifType variable in the Internet-
   standard MIB:

        ds1 (18)

   The definitions contained herein are based on the AT&T T-1 Superframe
   (a.k.a., D4) and Extended Superframe (ESF) formats [6, 7], the latter
   of which conforms to ANSI specifications [8], and the CCITT
   Recommendations [9, 10], referred to as E1 for the rest of this memo.

   The various DS1 and E1 line disciplines are similar enough that
   separate MIBs are unwarranted, although there are some differences.
   For example, Loss of Frame is defined more rigorously in the ESF
   specification than in the D4 specification, but it is defined in
   both.  Therefore,  interface types e1(19) and g703at2mb(67) have been
   obsoleted.

   Where it is necessary to distinguish between the flavors of E1 with
   and without CRC, E1-CRC denotes the "with CRC" form (G.704 Table 4b)
   and E1-noCRC denotes the "without CRC" form (G.704 Table 4a).

3.1.  Use of ifTable for DS1 Layer

   Only the ifGeneralGroup needs to be supported.

           ifTable Object    Use for DS1 Layer
======================================================================
           ifIndex           Interface index.

           ifDescr           See interfaces MIB [21]

           ifType            ds1(18)

           ifSpeed           Speed of line rate
                             DS1 - 1544000
                             E1  - 2048000
                             DS2 - 6312000
                             E2  - 8448000

           ifPhysAddress     The value of the Circuit Identifier.

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                             If no Circuit Identifier has been assigned
                             this object should have an octet string
                             with zero length.

           ifAdminStatus     See interfaces MIB [21]

           ifOperStatus      See interfaces MIB [21]

           ifLastChange      See interfaces MIB [21]

           ifName            See interfaces MIB [21].

           ifLinkUpDownTrapEnable   Set to enabled(1).

           ifHighSpeed       Speed of line in Mega-bits per second
                             (2, 6, or 8)

           ifConnectorPresent Set to true(1) normally, except for
                              cases such as DS1/E1 over AAL1/ATM where
                              false(2) is appropriate

3.2.  Usage Guidelines

3.2.1.  Usage of ifStackTable for Routers and DSUs

   The object dsx1IfIndex has been deprecated.  This object previously
   allowed a very special proxy situation to exist for Routers and CSUs.
   This section now describes how to use ifStackTable to represent this
   relationship.

   The paragraphs discussing dsx1IfIndex and dsx1LineIndex have been
   preserved in Appendix A for informational purposes.

   The ifStackTable is used in the proxy case to represent the
   association between pairs of interfaces, e.g. this T1 is attached to
   that T1.  This use is consistent with the use of the ifStackTable to
   show the association between various sub-layers of an interface.  In
   both cases entire PDUs are exchanged between the interface pairs - in
   the case of a T1, entire T1 frames are exchanged; in the case of PPP
   and HDLC, entire HDLC frames are exchanged.  This usage is not meant
   to suggest the use of the ifStackTable to represent Time Division
   Multiplexing (TDM) connections in general.

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   External&Internal interface scenario: the SNMP Agent resides on a
   host external from the device supporting DS1 interfaces (e.g., a
   router). The Agent represents both the host and the DS1 device.

   Example:

   A shelf full of CSUs connected to a Router. An SNMP Agent residing on
   the router proxies for itself and the CSU. The router has also an
   Ethernet interface:

         +-----+
   |     |     |
   |     |     |               +---------------------+
   |E    |     |  1.544  MBPS  |              Line#A | DS1 Link
   |t    |  R  |---------------+ - - - - -  - - -  - +------>
   |h    |     |               |                     |
   |e    |  O  |  1.544  MBPS  |              Line#B | DS1 Link
   |r    |     |---------------+ - - - - - - - - - - +------>
   |n    |  U  |               |  CSU Shelf          |
   |e    |     |  1.544  MBPS  |              Line#C | DS1 Link
   |t    |  T  |---------------+ - - - -- -- - - - - +------>
   |     |     |               |                     |
   |-----|  E  |  1.544  MBPS  |              Line#D | DS1 Link
   |     |     |---------------+ -  - - - -- - - - - +------>
   |     |  R  |               |_____________________|
   |     |     |
   |     +-----+

   The assignment of the index values could for example be:

           ifIndex  Description
           1        Ethernet
           2        Line#A Router
           3        Line#B Router
           4        Line#C Router
           5        Line#D Router
           6        Line#A CSU Router
           7        Line#B CSU Router
           8        Line#C CSU Router
           9        Line#D CSU Router
           10       Line#A CSU Network
           11       Line#B CSU Network
           12       Line#C CSU Network
           13       Line#D CSU Network

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   The ifStackTable is then used to show the relationships between the
   various DS1 interfaces.

           ifStackTable Entries

           HigherLayer   LowerLayer
           2             6
           3             7
           4             8
           5             9
           6             10
           7             11
           8             12
           9             13

   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be identical, except the Ethernet and the 4 router
   interfaces are deleted.  Interfaces would also be numbered from 1 to
   8.

           ifIndex  Description
           1        Line#A CSU Router
           2        Line#B CSU Router
           3        Line#C CSU Router
           4        Line#D CSU Router
           5        Line#A CSU Network
           6        Line#B CSU Network
           7        Line#C CSU Network
           8        Line#D CSU Network

           ifStackTable Entries

           HigherLayer   LowerLayer
           1             5
           2             6
           3             7
           4             8

3.2.2.  Usage of ifStackTable for DS1/E1 on DS2/E2

An example is given of how DS1/E2 interfaces are stacked on DS2/E2
interfaces.  It is not necessary nor is it always desirable to represent
DS2 interfaces.  If this is required, the following stacking should be
used.  All ifTypes are ds1.  The DS2 is determined by examining ifSpeed
or dsx1LineType.

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        ifIndex  Description
        1        DS1 #1
        2        DS1 #2
        3        DS1 #3
        4        DS1 #4
        5        DS2

        ifStackTable Entries

        HigherLayer   LowerLayer
        1             5
        2             5
        3             5
        4             5

3.2.3.  Usage of Channelization for DS3, DS1, DS0

An example is given here to explain the channelization objects in the
DS3, DS1, and DS0 MIBs to help the implementor use the objects
correctly.

Assume that a DS3 (with ifIndex 1) is Channelized into DS1s (without
DS2s).  The object dsx3Channelization is set to enabledDs1.  There will
be 28 DS1s in the ifTable.  Assume the entries in the ifTable for the
DS1s are created in channel order and the ifIndex values are 2 through
29. In the DS1 MIB, there will be an entry in the dsx1ChanMappingTable
for each ds1.  The entries will be as follows:

        dsx1ChanMappingTable Entries

        ifIndex  dsx1Ds1ChannelNumber   dsx1ChanMappedIfIndex
        1        1                      2
        1        2                      3
        ......
        1        28                     29

In addition, the DS1s are channelized into DS0s.  The object
dsx1Channelization is set to enabledDS0 for each DS1.  There will be 24
DS0s in the ifTable for each DS1.  Assume the entries in the ifTable are
created in channel order and the ifIndex values for the DS0s in the
first DS1 are 30 through 53.  In the DS0 MIB, there will be an entry in
the dsx0ChanMappingTable for each DS0.  The entries will be as follows:

        dsx0ChanMappingTable Entries

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        ifIndex   dsx0Ds0ChannelNumber  dsx0ChanMappedIfIndex
        2         1                     30
        2         2                     31
        ......
        2         24                    53

3.2.4.  Usage of Channelization for DS3, DS2, DS1

An example is given here to explain the channelization objects in the
DS3 and DS1 MIBs to help the implementor use the objects correctly.

Assume that a DS3 (with ifIndex 1) is Channelized into DS2s.  The object
dsx3Channelization is set to enabledDs2.  There will be 7 DS2s (ifType
of DS1) in the ifTable.  Assume the entries in the ifTable for the DS2s
are created in channel order and the ifIndex values are 2 through 8. In
the DS1 MIB, there will be an entry in the dsx1ChanMappingTable for each
DS2.  The entries will be as follows:

        dsx1ChanMappingTable Entries

        ifIndex  dsx1Ds1ChannelNumber   dsx1ChanMappedIfIndex
        1        1                      2
        1        2                      3
        ......
        1        7                      8

In addition, the DS2s are channelized into DS1s.  The object
dsx1Channelization is set to enabledDS1 for each DS2.  There will be
4 DS1s in the ifTable for each DS2.  Assume the entries in the ifTable
are created in channel order and the ifIndex values for the DS1s in
the first DS2 are 9 through 12, then 13 through 16 for the second DS2,
and so on.  In the DS1 MIB, there will be an
entry in the dsx1ChanMappingTable for each DS1.  The entries will
be as follows:

        dsx1ChanMappingTable Entries

        ifIndex   dsx1Ds1ChannelNumber  dsx1ChanMappedIfIndex
        2         1                     9
        2         2                     10
        2         3                     11
        2         4                     12
        3         1                     13
        3         2                     14
        ...

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        8         4                     36

3.2.5.  Usage of Loopbacks

This section discusses the behaviour of objects related to loopbacks.

The object dsx1LoopbackConfig represents the desired state of loopbacks
on this interface.  Using this object a Manager can request:
    LineLoopback
    PayloadLoopback (if ESF framing)
    InwardLoopback
    DualLoopback (Line + Inward)
    NoLoopback

The remote end can also request lookbacks either through the FDL channel
if ESF or inband if D4.  The loopbacks that can be request this way are:
    LineLoopback
    PayloadLoopback (if ESF framing)
    NoLoopback

To model the current state of loopbacks on a DS1 interface, the object
dsx1LoopbackStatus defines which loopback is currently applies to an
interface.  This objects, which is a bitmap, will have bits turned on
which reflect the currently active loopbacks on the interface as well as
the source of those loopbacks.

The following restrictions/rules apply to loopbacks:

The far end cannot undo loopbacks set by a manager.

A manager can undo loopbacks set by the far end.

Both a line loopback and an inward loopback can be set at the same time.
Only these two loopbacks can co-exist and either one may be set by the
manager or the far end.  A LineLoopback request from the far end is
incremental to an existing Inward loopback established by a manager.
When a NoLoopback is received from the far end in this case, the
InwardLoopback remains in place.

3.3.  Objectives of this MIB Module

   There are numerous things that could be included in a MIB for DS1
   signals:  the management of multiplexors, CSUs, DSUs, and the like.

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   The intent of this document is to facilitate the common management of
   all devices with DS1, E1, DS2, or E3 interfaces.  As such, a design
   decision was made up front to very closely align the MIB with the set
   of objects that can generally be read from these types devices that
   are currently deployed.

   J2 interfaces are not supported by this MIB.

3.4.  DS1 Terminology

   The terminology used in this document to describe error conditions on
   a DS1 interface as monitored by a DS1 device are based on the late
   but not final draft of what became the ANSI T1.231 standard [11].  If
   the definition in this document does not match the definition in the
   ANSI T1.231 document, the implementer should follow the definition
   described in this document.

3.4.1.  Error Events

     Bipolar Violation (BPV) Error Event
          A BPV error event for an AMI-coded signal is the occurrence of
          a pulse of the same polarity as the previous pulse.  (See
          T1.231 Section 6.1.1.1.1) A BPV error event for a B8ZS- or
          HDB3- coded signal is the occurrence of a pulse of the same
          polarity as the previous pulse without being a part of the
          zero substitution code.

     Excessive Zeroes (EXZ) Error Event
          An Excessive Zeroes error event for an AMI-coded signal is the
          occurrence of more than fifteen contiguous zeroes.  (See
          T1.231 Section 6.1.1.1.2) For a B8ZS coded signal, the defect
          occurs when more than seven contiguous zeroes are detected.

      Line Coding Violation (LCV) Error Event
          A Line Coding Violation (LCV) is the occurrence of either a
          Bipolar Violation (BPV) or Excessive Zeroes (EXZ) Error Event.
          (Also known as CV-L; See T1.231 Section 6.5.1.1)

     Path Coding Violation (PCV) Error Event
          A Path Coding Violation error event is a frame synchronization
          bit error in the D4 and E1-noCRC formats, or a CRC or frame
          synch. bit error in the ESF and E1-CRC formats. (Also known as
          CV-P; See T1.231 Section 6.5.2.1)

     Controlled Slip (CS) Error Event

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          A Controlled Slip is the replication or deletion of the
          payload bits of a DS1 frame.  (See T1.231 Section 6.1.1.2.3) A
          Controlled Slip may be performed when there is a difference
          between the timing of a synchronous receiving terminal and the
          received signal.  A Controlled Slip does not cause an Out of
          Frame defect.

3.4.2.  Performance Defects

     Out Of Frame (OOF) Defect
          An OOF defect is the occurrence of a particular density of
          Framing Error events. (See T1.231 Section 6.1.2.2.1)

          For DS1 links, an Out of Frame defect is declared when the
          receiver detects two or more framing errors within a 3 msec
          period for ESF signals and 0.75 msec for D4 signals, or two or
          more errors out of five or fewer consecutive framing-bits.

          For E1 links, an Out Of Frame defect is declared when three
          consecutive frame alignment signals have been received with an
          error (see G.706 Section 4.1 [15]).

          For DS2 links, an Out of Frame defect is declared when 7 or
          more consecutive errored framing patterns (4 multiframe) are
          received.  The LOF is cleared when 3 or more consecutive
          correct framing patterns are received.

          Once an Out Of Frame Defect is declared, the framer starts
          searching for a correct framing pattern.  The Out of Frame
          defect ends when the signal is in frame.

          In-frame occurs when there are fewer than two frame bit errors
          within 3 msec period for ESF signals and 0.75 msec for D4
          signals.

          For E1 links, in-frame occurs when a) in frame N the frame
          alignment signal is correct and b) in frame N+1 the frame
          alignment signal is absent (i.e., bit 2 in TS0 is a one) and
          c) in frame N+2 the frame alignment signal is present and
          correct. (See G.704 Section 4.1)

     Alarm Indication Signal (AIS) Defect
          For D4 and ESF links, the 'all ones' condition is detected at
          a DS1 line interface upon observing an unframed signal with a
          one's density of at least 99.9% present for a time equal to or

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          greater than T, where 3 ms <= T <= 75 ms.  The AIS is
          terminated upon observing a signal not meeting the one's
          density or the unframed signal criteria for a period equal to
          or greater than than T. (See G.775, Section 5.4)

          For E1 links, the 'all-ones' condition is detected at the line
          interface as a string of 512 bits containing fewer than three
          zero bits (see O.162 [12] Section 3.3.2).

          For DS2 links, the DS2 AIS shall be sent from the NT1 to the
          user to indicate a loss of the 6,312 kbps frame capability on
          the network side.  The DS2 AIS is defined as a bit array of
          6,312 kbps in which all binary bits are set to '1'.

          The DS2 AIS detection and removal shall be implemented
          according to ITU-T Draft Recommendation G.775[20] Section 5.5:
          - a DS2 AIS defect is detected when the incoming signal has
          two (2) or less ZEROs in a sequence of 3156 bits (0.5 ms).
          - a DS2 AIS defect is cleared when the incoming signal has
          three (3) or more ZEROs in a sequence of 3156 bits (0.5 ms).

3.4.3.  Performance Parameters

   All performance parameters are accumulated in fifteen minute
   intervals and up to 96 intervals (24 hours worth) are kept by an
   agent.  Fewer than 96 intervals of data will be available if the
   agent has been restarted within the last 24 hours.  In addition,
   there is a rolling 24-hour total of each performance parameter.
   Performance parameters continue to be collected when the interface is
   down.

   There is no requirement for an agent to ensure fixed relationship
   between the start of a fifteen minute interval and any wall clock;
   however some agents may align the fifteen minute intervals with
   quarter hours.

   Performance parameters are of types PerfCurrentCount,
   PerfIntervalCount and PerfTotalCount.  These textual conventions are
   all Gauge32, and they are used because it is possible for these
   objects to decrease.  Objects may decrease when Unavailable Seconds
   occurs across a fifteen minutes interval boundary. See Unavailable
   Seconds discussion later in this section.

     Line Errored Seconds (LES)

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          A Line Errored Second is a second in which one or more Line
          Code Violation error events were detected. (Also known as ES-
          L; See T1.231 Section 6.5.1.2)

     Controlled Slip Seconds (CSS)
          A Controlled Slip Second is a one-second interval containing
          one or more controlled slips.  (See T1.231 Section 6.5.2.8)
          This is not incremented during an Unavailable Second.

     Errored Seconds (ES)
          For ESF and E1-CRC links an Errored Second is a second with
          one or more Path Code Violation OR one or more Out of Frame
          defects OR one or more Controlled Slip events OR a detected
          AIS defect. (See T1.231 Section 6.5.2.2 and G.826[22] Section
          B.1)

          For D4 and E1-noCRC links, the presence of Bipolar Violations
          also triggers an Errored Second.

          This is not incremented during an Unavailable Second.

     Bursty Errored Seconds (BES)
          A Bursty Errored Second (also known as Errored Second type B
          in T1.231 Section 6.5.2.4) is a second with fewer than 320 and
          more than 1 Path Coding Violation error events, no Severely
          Errored Frame defects and no detected incoming AIS defects.
          Controlled slips are not included in this parameter.

          This is not incremented during an Unavailable Second.  It
          applies to ESF signals only.

     Severely Errored Seconds (SES)
          A Severely Errored Second for ESF signals is a second with 320
          or more Path Code Violation Error Events OR one or more Out of
          Frame defects OR a detected AIS defect. (See T1.231 Section
          6.5.2.5)

          For E1-CRC signals, a Severely Errored Second is a second with
          832 or more Path Code Violation error events OR one or more
          Out of Frame defects.

          For E1-noCRC signals, a Severely Errored Second is a 2048 LCVs
          or more.

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          For D4 signals, a Severely Errored Second is a count of one-
          second intervals with Framing Error events, or an OOF defect,
          or 1544 LCVs or more.

          Controlled slips are not included in this parameter.

          This is not incremented during an Unavailable Second.

     Severely Errored Framing Second (SEFS)
          An Severely Errored Framing Second is a second with one or
          more Out of Frame defects OR a detected AIS defect.  (Also
          known as SAS-P (SEF/AIS second); See T1.231 Section 6.5.2.6)

     Degraded Minutes
          A Degraded Minute is one in which the estimated error rate
          exceeds 1E-6 but does not exceed 1E-3 (see G.821[13]).

          Degraded Minutes are determined by collecting all of the
          Available Seconds, removing any Severely Errored Seconds
          grouping the result in 60-second long groups and counting a
          60-second long group (a.k.a., minute) as degraded if the
          cumulative errors during the seconds present in the group
          exceed 1E-6.  Available seconds are merely those seconds which
          are not Unavailable as described below.

     Unavailable Seconds (UAS)
          Unavailable Seconds (UAS) are calculated by counting the
          number of seconds that the interface is unavailable.  The DS1
          interface is said to be unavailable from the onset of 10
          contiguous SESs, or the onset of the condition leading to a
          failure (see Failure States).  If the condition leading to the
          failure was immediately preceded by one or more contiguous
          SESs, then the DS1 interface unavailability starts from the
          onset of these SESs.  Once unavailable, and if no failure is
          present, the DS1 interface becomes available at the onset of
          10 contiguous seconds with no SESs.  Once unavailable, and if
          a failure is present, the DS1 interface becomes available at
          the onset of 10 contiguous seconds with no SESs, if the
          failure clearing time is less than or equal to 10 seconds.  If
          the failure clearing time is more than 10 seconds, the DS1
          interface becomes available at the onset of 10 contiguous
          seconds with no SESs, or the onset period leading to the
          successful clearing condition, whichever occurs later.  With
          respect to the DS1 error counts, all counters are incremented
          while the DS1 interface is deemed available.  While the

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          interface is deemed unavailable, the only count that is
          incremented is UASs.

          Note that this definition implies that the agent cannot
          determine until after a ten second interval has passed whether
          a given one-second interval belongs to available or
          unavailable time.  If the agent chooses to update the various
          performance statistics in real time then it must be prepared
          to retroactively reduce the ES, BES, SES, and SEFS counts by
          10 and increase the UAS count by 10 when it determines that
          available time has been entered.  It must also be prepared to
          adjust the PCV count and the DM count as necessary since these
          parameters are not accumulated during unavailable time.  It
          must be similarly prepared to retroactively decrease the UAS
          count by 10 and increase the ES, BES, and DM counts as
          necessary upon entering available time.  A special case exists
          when the 10 second period leading to available or unavailable
          time crosses a 900 second statistics window boundary, as the
          foregoing description implies that the ES, BES, SES, SEFS, DM,
          and UAS counts the PREVIOUS interval must be adjusted.  In
          this case successive GETs of the affected dsx1IntervalSESs and
          dsx1IntervalUASs objects will return differing values if the
          first GET occurs during the first few seconds of the window.

          The agent may instead choose to delay updates to the various
          statistics by 10 seconds in order to avoid retroactive
          adjustments to the counters.  A way to do this is sketched in
          Appendix B.

          In any case, a linkDown trap shall be sent only after the
          agent has determined for certain that the unavailable state
          has been entered, but the time on the trap will be that of the
          first UAS (i.e., 10 seconds earlier).  A linkUp trap shall be
          handled similarly.

          According to ANSI T1.231 unavailable time begins at the
          _onset_ of 10 contiguous severely errored seconds -- that is,
          unavailable time starts with the _first_ of the 10 contiguous
          SESs.  Also, while an interface is deemed unavailable all
          counters for that interface are frozen except for the UAS
          count.  It follows that an implementation which strictly
          complies with this standard must _not_ increment any counters
          other than the UAS count -- even temporarily -- as a result of
          anything that happens during those 10 seconds.  Since changes
          in the signal state lag the data to which they apply by 10

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          seconds, an ANSI-compliant implementation must pass the the
          one-second statistics through a 10-second delay line prior to
          updating any counters.  That can be done by performing the
          following steps at the end of each one second interval.

   i)   Read near/far end CV counter and alarm status flags from the
        hardware.

   ii)  Accumulate the CV counts for the preceding second and
        compare them to the ES and SES threshold for the layer
        in question.  Update the signal state and shift the
        one-second CV counts and ES/SES flags into the 10-element
        delay line.  Note that far-end one-second statistics are
        to be flagged as "absent" during any second in which there
        is an incoming defect at the layer in question or at any
        lower layer.

   iii) Update the current interval statistics using the signal
        state from the _previous_ update cycle and the one-second
        CV counts and ES/SES flags shifted out of the 10-element
        delay line.

   This approach is further described in Appendix B.

3.4.4.  Failure States

The following failure states are received, or detected failures, that
are reported in the dsx1LineStatus object.  When a DS1 interface would,
if ever, produce the conditions leading to the failure state is
described in the appropriate specification.

     Far End Alarm Failure
          The Far End Alarm failure is also known as "Yellow Alarm" in
          the DS1 case, "Distant Alarm" in the E1 case, and "Remote
          Alarm" in the DS2 case.

          For D4 links, the Far End Alarm failure is declared when bit 6
          of all channels has been zero for at least 335 ms and is
          cleared when bit 6 of at least one channel is non-zero for a
          period T, where T is usually less than one second and always
          less than 5 seconds.  The Far End Alarm failure is not
          declared for D4 links when a Loss of Signal is detected.

          For ESF links, the Far End Alarm failure is declared if the
          Yellow Alarm signal pattern occurs in at least seven out of

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          ten contiguous 16-bit pattern intervals and is cleared if the
          Yellow Alarm signal pattern does not occur in ten contiguous
          16-bit signal pattern intervals.

          For E1 links, the Far End Alarm failure is declared when bit 3
          of time-slot zero is received set to one on two consecutive
          occasions.  The Far End Alarm failure is cleared when bit 3 of
          time-slot zero is received set to zero.

          For DS2 links, if a loss of frame alignment (LOF or LOS)
          and/or DS2 AIS condition, is detected, the RAI signal shall be
          generated and transmitted to the remote side.

          The Remote Alarm Indication(RAI) signal is defined on m-bits
          as a repetition of the 16bit sequence consisting of eight
          binary '1s' and eight binary '0s' in m-bits(1111111100000000).
          When the RAI signal is not sent (in normal operation),the HDLC
          flag pattern (01111110) in the m-bit is sent.

          The RAI failure is detected when 16 or more consecutive RAI-
          patterns (1111111100000000) are received.  The RAI failure is
          cleared when 4 or more consecutive incorrect-RAI-patterns are
          received.

     Alarm Indication Signal (AIS) Failure
          The Alarm Indication Signal failure is declared when an AIS
          defect is detected at the input and the  AIS defect still
          exists after the Loss Of Frame failure (which is caused by the
          unframed nature of the 'all-ones' signal) is declared. The AIS
          failure is cleared when the Loss Of Frame failure is cleared.
          (See T1.231 Section 6.2.1.2.1)

          An AIS defect at a 6312 kbit/s (G.704) interface is detected
          when the incoming signal has two {2} or less ZEROs in a
          sequence of 3156 bits (0.5ms).

          The AIS signal defect is cleared when the incoming signal has
          three {3} or more ZEROs in a sequence of 3156 bits (0.5ms).

     Loss Of Frame Failure
          For DS1 links, the Loss Of Frame failure is declared when an
          OOF or LOS  defect has persisted for T seconds, where 2 <= T
          <= 10.  The Loss Of Frame failure is cleared when there have
          been no OOF or LOS defects during a period T where 0 <= T <=
          20.  Many systems will perform "hit integration" within the

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          period T before declaring or clearing the failure e.g., see TR
          62411 [14].

          For E1 links, the Loss Of Frame Failure is declared when an
          OOF defect is detected.

     Loss Of Signal Failure
          For DS1, the Loss Of Signal failure is declared upon observing
          175 +/- 75 contiguous pulse positions with no pulses of either
          positive or negative polarity.  The LOS failure is cleared
          upon observing an average pulse density of at least 12.5% over
          a period of 175 +/- 75 contiguous pulse positions starting
          with the receipt of a pulse.

          For E1 links, the Loss Of Signal failure is declared when
          greater than 10 consecutive zeroes are detected (see O.162
          Section 3.4`<.4).

          A LOS defect at 6312kbit/s interfaces is detected when the
          incoming signal has "no transitions", i.e. when the signal
          level is less than or equal to a signal level of 35dB below
          nominal, for N consecutive pulse intervals, where 10 <=N<=255.

          The LOS defect is cleared when the incoming signal has
          "transitions", i.e. when the signal level is greater than or
          equal to a signal level of 9dB below nominal, for N
          consecutive pulse intervals, where 10<=N<=255.

          A signal with "transitions" corresponds to a G.703 compliant
          signal.

     Loopback Pseudo-Failure
          The Loopback Pseudo-Failure is declared when the near end
          equipment has placed a loopback (of any kind) on the DS1.
          This allows a management entity to determine from one object
          whether the DS1 can be considered to be in service or not
          (from the point of view of the near end equipment).

     TS16 Alarm Indication Signal Failure
          For E1 links, the TS16 Alarm Indication Signal failure is
          declared when time-slot 16 is received as all ones for all
          frames of two consecutive multiframes (see G.732 Section
          4.2.6).  This condition is never declared for DS1.

     Loss Of MultiFrame Failure

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          The Loss Of MultiFrame failure is declared when two
          consecutive multiframe alignment signals (bits 4 through 7 of
          TS16 of frame 0) have been received with an error.  The Loss
          Of Multiframe failure is cleared when the first correct
          multiframe alignment signal is received.  The Loss Of
          Multiframe failure can only be declared for E1 links operating
          with G.732 [16] framing (sometimes called "Channel Associated
          Signalling" mode).

     Far End Loss Of Multiframe Failure
          The Far End Loss Of Multiframe failure is declared when bit 2
          of TS16 of frame 0 is received set to one on two consecutive
          occasions.  The Far End Loss Of Multiframe failure is cleared
          when bit 2 of TS16 of frame 0 is received set to zero.  The
          Far End Loss Of Multiframe failure can only be declared for E1
          links operating in "Channel Associated Signalling" mode. (See
          G.732)

     DS2 Payload AIS Failure
          The DS2 Payload AIS is detected when the incoming signal of
          the 6,312 kbps frame payload [TS1-TS96] has 2 or less 0's in a
          sequence of 3072 bits (0.5ms).  The DS2 Payload AIS is cleared
          when the incoming signal of the 6,312 kbps frame payload
          [TS1-TS96] has 3 or more 0's in a sequence of 3072 bits (0.5
          ms).

     DS2 Performance Threshold
          DS2 Performance Threshold Failure monitors equipment
          performance and is based on the CRC (Cyclic Redundancy Check)
          Procedure defined in G.704.

          The DS2 Performance Threshold Failure is detected when the bit
          error ratio exceeds 10^-4 (Performance Threshold), and the DS2
          Performance Threshold Failure shall be cleared when the bit
          error ratio decreased to less than 10^-6."

3.4.5.  Other Terms
          Circuit Identifier
            This is a character string specified by the circuit
            vendor, and is useful when communicating with the vendor
            during the troubleshooting process.

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4.  Object Definitions

          DS1-MIB DEFINITIONS ::= BEGIN

          IMPORTS
               MODULE-IDENTITY, OBJECT-TYPE,
               NOTIFICATION-TYPE, transmission         FROM SNMPv2-SMI
               DisplayString, TimeStamp, TruthValue    FROM SNMPv2-TC
               MODULE-COMPLIANCE, OBJECT-GROUP,
               NOTIFICATION-GROUP                      FROM SNMPv2-CONF
               InterfaceIndex, ifIndex                 FROM IF-MIB
               PerfCurrentCount, PerfIntervalCount,
               PerfTotalCount                          FROM PerfHist-TC-MIB;

          ds1 MODULE-IDENTITY
              LAST-UPDATED "9802112330Z"
              ORGANIZATION "IETF Trunk MIB Working Group"
              CONTACT-INFO
                "        David Fowler

                 Postal: Newbridge Networks Corporation
                         600 March Road
                         Kanata, Ontario, Canada K2K 2E6

                         Tel: +1 613 591 3600
                         Fax: +1 613 599 3667

                 E-mail: [email-masked]"
              DESCRIPTION
                   "The MIB module to describe DS1, E1, DS2, and
                    E2 interfaces objects."

              ::= { transmission 18 }

          -- note that this subsumes cept (19) and g703at2mb (67)
          -- there is no separate CEPT or G703AT2MB MIB

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          -- The DS1 Near End Group

          -- The DS1 Near End Group consists of four tables:
          --    DS1 Configuration
          --    DS1 Current
          --    DS1 Interval
          --    DS1 Total
          --    DS1 Channel Table

          -- The DS1 Configuration Table

          dsx1ConfigTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1ConfigEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Configuration table."
               ::= { ds1 6 }

          dsx1ConfigEntry OBJECT-TYPE
               SYNTAX  Dsx1ConfigEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Configuration table."
               INDEX   { dsx1LineIndex }
               ::= { dsx1ConfigTable 1 }

          Dsx1ConfigEntry ::=
               SEQUENCE {
                   dsx1LineIndex                        InterfaceIndex,
                   dsx1IfIndex                          InterfaceIndex,
                   dsx1TimeElapsed                      INTEGER,
                   dsx1ValidIntervals                   INTEGER,
                   dsx1LineType                         INTEGER,
                   dsx1LineCoding                       INTEGER,
                   dsx1SendCode                         INTEGER,
                   dsx1CircuitIdentifier                DisplayString,
                   dsx1LoopbackConfig                   INTEGER,
                   dsx1LineStatus                       INTEGER,
                   dsx1SignalMode                       INTEGER,
                   dsx1TransmitClockSource              INTEGER,
                   dsx1Fdl                              INTEGER,
                   dsx1InvalidIntervals                 INTEGER,
                   dsx1LineLength                       INTEGER,

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                   dsx1LineStatusLastChange             TimeStamp,
                   dsx1LineStatusChangeTrapEnable       INTEGER,
                   dsx1LoopbackStatus                   INTEGER,
                   dsx1Ds1ChannelNumber                 INTEGER,
                   dsx1Channelization                   INTEGER
          }

          dsx1LineIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "This object should be made equal to ifIndex.  The
                      next paragraph describes its previous usage.
                      Making the object equal to ifIndex allows proper
                      use of ifStackTable and ds0/ds0bundle mibs.

                      Previously, this object is the identifier of a DS1
                      Interface on a managed device.  If there is an
                      ifEntry that is directly associated with this and
                      only this DS1 interface, it should have the same
                      value as ifIndex.  Otherwise, number the
                      dsx1LineIndices with an unique identifier
                      following the rules of choosing a number that is
                      greater than ifNumber and numbering the inside
                      interfaces (e.g., equipment side) with even
                      numbers and outside interfaces (e.g, network side)
                      with odd numbers."
               ::= { dsx1ConfigEntry 1 }

          dsx1IfIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  deprecated
               DESCRIPTION
                      "This value for this object is equal to the value
                      of ifIndex from the Interfaces table of MIB II
                      (RFC 1213)."
               ::= { dsx1ConfigEntry 2 }

          dsx1TimeElapsed OBJECT-TYPE
               SYNTAX  INTEGER (0..899)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION

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                      "The number of seconds that have elapsed since the
                      beginning of the near end current error-
                      measurement period."
               ::= { dsx1ConfigEntry 3 }

          dsx1ValidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of previous near end intervals for
                      which valid data was collected.  The value will be
                      96 unless the interface was brought online within
                      the last 24 hours, in which case the value will be
                      the number of complete 15 minute near end
                      intervals since the interface has been online.  In
                      the case where the agent is a proxy, it is
                      possible that some intervals are unavailable.  In
                      this case, this interval is the maximum interval
                      number for which valid data is available."
               ::= { dsx1ConfigEntry 4 }

          dsx1LineType OBJECT-TYPE
               SYNTAX  INTEGER {
                          other(1),
                          dsx1ESF(2),
                          dsx1D4(3),
                          dsx1E1(4),
                          dsx1E1CRC(5),
                          dsx1E1MF(6),
                          dsx1E1CRCMF(7),
                          dsx1Unframed(8),
                          dsx1E1Unframed(9),
                          dsx1DS2M12(10),
                          dsx2E2(11)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable indicates  the  variety  of  DS1
                      Line  implementing  this  circuit.  The type of
                      circuit affects the number of bits  per  second
                      that  the circuit can reasonably carry, as well
                      as the interpretation of the  usage  and  error
                      statistics.  The values, in sequence, describe:

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                      TITLE:         SPECIFICATION:
                      dsx1ESF         Extended SuperFrame DS1 (T1.107)
                      dsx1D4          AT&T D4 format DS1 (T1.107)
                      dsx1E1          ITU-T Recommendation G.704
                                       (Table 4a)
                      dsx1E1-CRC      ITU-T Recommendation G.704
                                       (Table 4b)
                      dsxE1-MF        G.704 (Table 4a) with TS16
                                       multiframing enabled
                      dsx1E1-CRC-MF   G.704 (Table 4b) with TS16
                                       multiframing enabled
                      dsx1Unframed    DS1 with No Framing
                      dsx1E1Unframed  E1 with No Framing (G.703)
                      dsx1DS2M12      DS2 frame format (T1.107)
                      dsx1E2          E2 frame format (G.704)

                      For clarification, the capacity for each E1 type
                      is as listed below:
                      dsx1E1Unframed - E1, no framing = 32 x 64k = 2048k
                      dsx1E1 or dsx1E1CRC - E1, with framing,
                         no signalling = 31 x 64k = 1984k
                      dsx1E1MF or dsx1E1CRCMF - E1, with framing,
                         signalling = 30 x 64k = 1920k

                      For further information See ITU-T Recomm G.704"
               ::= { dsx1ConfigEntry 5 }

          dsx1LineCoding OBJECT-TYPE
               SYNTAX  INTEGER {
                          dsx1JBZS (1),
                          dsx1B8ZS (2),
                          dsx1HDB3 (3),
                          dsx1ZBTSI (4),
                          dsx1AMI (5),
                          other(6),
                          dsx1B6ZS(7)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable describes the variety of Zero Code
                      Suppression used on this interface, which in turn
                      affects a number of its characteristics.

                      dsx1JBZS refers the Jammed Bit Zero Suppression,

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                      in which the AT&T specification of at least one
                      pulse every 8 bit periods is literally implemented
                      by forcing a pulse in bit 8 of each channel.
                      Thus, only seven bits per channel, or 1.344 Mbps,
                      is available for data.

                      dsx1B8ZS refers to the use of a specified pattern
                      of normal bits and bipolar violations which are
                      used to replace a sequence of eight zero bits.

                      ANSI Clear Channels may use dsx1ZBTSI, or Zero
                      Byte Time Slot Interchange.

                      E1 links, with or without CRC, use dsx1HDB3 or
                      dsx1AMI.

                      dsx1AMI refers to a mode wherein no zero code
                      suppression is present and the line encoding does
                      not solve the problem directly.  In this
                      application, the higher layer must provide data
                      which meets or exceeds the pulse density
                      requirements, such as inverting HDLC data.

                      dsx1B6ZS refers to the user of a specifed pattern
                      of normal bits and bipolar violations which are
                      used to replace a sequence of six zero bits.  Used
                      for DS2."

               ::= { dsx1ConfigEntry 6 }

          dsx1SendCode OBJECT-TYPE
               SYNTAX  INTEGER {
                         dsx1SendNoCode(1),
                         dsx1SendLineCode(2),
                         dsx1SendPayloadCode(3),
                         dsx1SendResetCode(4),
                         dsx1SendQRS(5),
                         dsx1Send511Pattern(6),
                         dsx1Send3in24Pattern(7),
                         dsx1SendOtherTestPattern(8)
                         }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable indicates what type of code is

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                      being sent across the DS1 interface by the device.
                      Setting this variable causes the interface to send
                      the code requested.  The values mean:
                dsx1SendNoCode
                     sending looped or normal data

                dsx1SendLineCode
                     sending a request for a line loopback

                dsx1SendPayloadCode
                     sending a request for a payload loopback

                dsx1SendResetCode
                     sending a loopback termination request

                dsx1SendQRS
                     sending a Quasi-Random Signal  (QRS)  test
                     pattern

                dsx1Send511Pattern
                     sending a 511 bit fixed test pattern

                dsx1Send3in24Pattern
                     sending a fixed test pattern of 3 bits set
                     in 24

                dsx1SendOtherTestPattern
                     sending a test pattern  other  than  those
                     described by this object"
     ::= { dsx1ConfigEntry 7 }

          dsx1CircuitIdentifier OBJECT-TYPE
               SYNTAX  DisplayString (SIZE (0..255))
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable contains the transmission vendor's
                      circuit identifier, for the purpose of
                      facilitating troubleshooting."
               ::= { dsx1ConfigEntry 8 }

          dsx1LoopbackConfig OBJECT-TYPE
               SYNTAX  INTEGER {
                           dsx1NoLoop(1),
                           dsx1PayloadLoop(2),

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                           dsx1LineLoop(3),
                           dsx1OtherLoop(4),
                           dsx1InwardLoop(5),
                           dsx1DualLoop(6)
                         }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable represents the desired loopback
                      configuration of the DS1 interface.  Agents
                      supporting read/write access should return
                      badValue in response to a requested loopback state
                      that the interface does not support.  The values
                      mean:

                      dsx1NoLoop
                       Not in the loopback state.  A device that is not
                      capable of performing a loopback on the interface
                      shall always return this as its value.

                      dsx1PayloadLoop
                       The received signal at this interface is looped
                      through the device.  Typically the received signal
                      is looped back for retransmission after it has
                      passed through the device's framing function.

                      dsx1LineLoop
                       The received signal at this interface does not go
                      through the device (minimum penetration) but is
                      looped back out.

                      dsx1OtherLoop
                       Loopbacks that are not defined here.

                      dsx1InwardLoop
                       The transmitted signal at this interface is
                      looped back and received by the same interface.
                      What is transmitted onto the line is product
                      dependent.

                      dsx1DualLoop
                       Both dsx1LineLoop and dsx1InwardLoop will be
                      active simultaneously."
               ::= { dsx1ConfigEntry 9 }

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          dsx1LineStatus OBJECT-TYPE
               SYNTAX  INTEGER (1..131071)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "This variable indicates the Line Status of the
                      interface.  It contains loopback, failure,
                      received 'alarm' and transmitted 'alarms
                      information.

                      The dsx1LineStatus is a bit map represented as a
                      sum, therefore, it can represent multiple failures
                      (alarms) and a LoopbackState simultaneously.

                      dsx1NoAlarm must be set if and only if no other
                      flag is set.

                      If the dsx1loopbackState bit is set, the loopback
                      in effect can be determined from the
                      dsx1loopbackConfig object.
            The various bit positions are:
           1     dsx1NoAlarm           No alarm present
           2     dsx1RcvFarEndLOF      Far end LOF (a.k.a., Yellow Alarm)
           4     dsx1XmtFarEndLOF      Near end sending LOF Indication
           8     dsx1RcvAIS            Far end sending AIS
          16     dsx1XmtAIS            Near end sending AIS
          32     dsx1LossOfFrame       Near end LOF (a.k.a., Red Alarm)
          64     dsx1LossOfSignal      Near end Loss Of Signal
         128     dsx1LoopbackState     Near end is looped
         256     dsx1T16AIS            E1 TS16 AIS
         512     dsx1RcvFarEndLOMF     Far End Sending TS16 LOMF
        1024     dsx1XmtFarEndLOMF     Near End Sending TS16 LOMF
        2048     dsx1RcvTestCode       Near End detects a test code
        4096     dsx1OtherFailure      any line status not defined here
        8192     dsx1UnavailSigState   Near End in Unavailable Signal
                                       State
       16384     dsx1NetEquipOOS       Carrier Equipment Out of Service
       32768     dsx1RcvPayloadAIS     DS2 Payload AIS
       65536     dsx1Ds2PerfThreshold  DS2 Performance Threshold
                                       Exceeded"
          ::= { dsx1ConfigEntry 10 }

          dsx1SignalMode OBJECT-TYPE
               SYNTAX  INTEGER {
                          none (1),

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                          robbedBit (2),
                          bitOriented (3),
                          messageOriented (4),
                          other (5)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                 "'none' indicates that no bits are reserved for
                 signaling on this channel.

                 'robbedBit' indicates that DS1 Robbed Bit  Sig-
                 naling is in use.

                 'bitOriented' indicates that E1 Channel  Asso-
                 ciated Signaling is in use.

                 'messageOriented' indicates that Common  Chan-
                 nel Signaling is in use either on channel 16 of
                 an E1 link or channel 24 of a DS1."
               ::= { dsx1ConfigEntry 11 }

          dsx1TransmitClockSource OBJECT-TYPE
               SYNTAX  INTEGER {
                          loopTiming(1),
                          localTiming(2),
                          throughTiming(3)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                 "The source of Transmit Clock.
                  'loopTiming' indicates that the recovered re-
                 ceive clock is used as the transmit clock.

                  'localTiming' indicates that a local clock
                 source is used or when an external clock is
                 attached to the box containing the interface.

                  'throughTiming' indicates that recovered re-
                 ceive clock from another interface is used as
                 the transmit clock."
               ::= { dsx1ConfigEntry 12 }

          dsx1Fdl OBJECT-TYPE

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               SYNTAX  INTEGER (1..15)
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                 "This bitmap describes the use of  the  facili-
                 ties data link, and is the sum of the capabili-
                 ties.  Set any bits that are appropriate:

                 other(1),
                 dsx1AnsiT1403(2),
                 dsx1Att54016(4),
                 dsx1FdlNone(8)

                  'other' indicates that a protocol  other  than
                 one following is used.

                  'dsx1AnsiT1403' refers to the  FDL  exchange
                 recommended by ANSI.

                  'dsx1Att54016' refers to ESF FDL exchanges.

                  'dsx1FdlNone' indicates that the device  does
                 not use the FDL."
               ::= { dsx1ConfigEntry 13 }

          dsx1InvalidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of intervals for which no valid data
                      is available."
               ::= { dsx1ConfigEntry 14 }

          dsx1LineLength OBJECT-TYPE
               SYNTAX  INTEGER (0..64000)
               UNITS  "meters"
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "The length of the ds1 line in meters. This
                      objects provides information for line build out
                      circuitry if it exists and can use this object to
                      adjust the line build out."
               ::= { dsx1ConfigEntry 15 }

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          dsx1LineStatusLastChange OBJECT-TYPE
               SYNTAX  TimeStamp
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The value of MIB II's sysUpTime object at the
                      time this DS1 entered its current line status
                      state.  If the current state was entered prior to
                      the last re-initialization of the proxy-agent,
                      then this object contains a zero value."
               ::= { dsx1ConfigEntry 16 }

          dsx1LineStatusChangeTrapEnable  OBJECT-TYPE
               SYNTAX      INTEGER {
                              enabled(1),
                              disabled(2)
                           }
               MAX-ACCESS  read-write
               STATUS      current
               DESCRIPTION
                      "Indicates whether dsx1LineStatusChange traps
                      should be generated for this interface."
               DEFVAL { disabled }
               ::= { dsx1ConfigEntry 17 }

          dsx1LoopbackStatus  OBJECT-TYPE
               SYNTAX      INTEGER (1..127)
               MAX-ACCESS  read-only
               STATUS      current
               DESCRIPTION
                      "This variable represents the current state of the
                      loopback on the DS1 interface.  It contains
                      information about loopbacks established by a
                      manager and remotely from the far end.

                      The dsx1LoopbackStatus is a bit map represented as
                      a sum, therefore is can represent multiple
                      loopbacks simultaneously.

                      The various bit positions are:
                       1  dsx1NoLoopback
                       2  dsx1NearEndPayloadLoopback
                       4  dsx1NearEndLineLoopback
                       8  dsx1NearEndOtherLoopback
                      16  dsx1NearEndInwardLoopback

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                      32  dsx1FarEndPayloadLoopback
                      64  dsx1FarEndLineLoopback"

          ::= { dsx1ConfigEntry 18 }

          dsx1Ds1ChannelNumber  OBJECT-TYPE
               SYNTAX      INTEGER (0..28)
               MAX-ACCESS  read-only
               STATUS      current
               DESCRIPTION
                      "This variable represents the channel number of
                      the DS1/E1 on its parent Ds2/E2 or DS3/E3.  A
                      value of 0 indicated this DS1/E1 does not have a
                      parent DS3/E3."

          ::= { dsx1ConfigEntry 19 }

          dsx1Channelization  OBJECT-TYPE
               SYNTAX      INTEGER {
                              disabled(1),
                              enabledDs0(2),
                              enabledDs1(3)
                           }
               MAX-ACCESS  read-write
               STATUS      current
               DESCRIPTION
                      "Indicates whether this ds1/e1 is channelized or
                      unchannelized.  The value of enabledDs0 indicates
                      that this is a DS1 channelized into DS0s.  The
                      value of enabledDs1 indicated that this is a DS2
                      channelized into DS1s.  "
          ::= { dsx1ConfigEntry 20 }

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          -- The DS1 Current Table
          dsx1CurrentTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1CurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 current table contains various statistics
                      being collected for the current 15 minute
                      interval."
               ::= { ds1 7 }

          dsx1CurrentEntry OBJECT-TYPE
               SYNTAX  Dsx1CurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Current table."
                           INDEX   { dsx1CurrentIndex }
                           ::= { dsx1CurrentTable 1 }

          Dsx1CurrentEntry ::=
               SEQUENCE {
                   dsx1CurrentIndex            InterfaceIndex,
                   dsx1CurrentESs              PerfCurrentCount,
                   dsx1CurrentSESs             PerfCurrentCount,
                   dsx1CurrentSEFSs            PerfCurrentCount,
                   dsx1CurrentUASs             PerfCurrentCount,
                   dsx1CurrentCSSs             PerfCurrentCount,
                   dsx1CurrentPCVs             PerfCurrentCount,
                   dsx1CurrentLESs             PerfCurrentCount,
                   dsx1CurrentBESs             PerfCurrentCount,
                   dsx1CurrentDMs              PerfCurrentCount,
                   dsx1CurrentLCVs             PerfCurrentCount
          }

          dsx1CurrentIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies  the
                      DS1 interface to which this entry is applicable.
                      The interface identified by a particular value of
                      this index is the same interface as identified by
                      the same value as a dsx1LineIndex object

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                      instance."
               ::= { dsx1CurrentEntry 1 }

          dsx1CurrentESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Errored Seconds, encountered  by a
                      DS1 interface in the current 15 minute interval.
                      noSuchInstance will be returned if no data is
                      available."
               ::= { dsx1CurrentEntry 2 }

          dsx1CurrentSESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Seconds
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1CurrentEntry 3 }

          dsx1CurrentSEFSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Framing Seconds
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1CurrentEntry 4 }

          dsx1CurrentUASs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds  encountered by
                      a DS1 interface in the current 15 minute interval.
                      noSuchInstance will be returned if no data is
                      available."

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               ::= { dsx1CurrentEntry 5 }

          dsx1CurrentCSSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Controlled Slip Seconds encountered
                      by a DS1 interface in the current 15 minute
                      interval.  noSuchInstance will be returned if no
                      data is available."
               ::= { dsx1CurrentEntry 6 }

          dsx1CurrentPCVs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Path Coding Violations encountered
                      by a DS1 interface in the current 15 minute
                      interval. noSuchInstance will be returned if no
                      data is available."
               ::= { dsx1CurrentEntry 7 }

          dsx1CurrentLESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Line Errored Seconds encountered by
                      a DS1 interface in the current 15 minute interval.
                      noSuchInstance will be returned if no data is
                      available."
               ::= { dsx1CurrentEntry 8 }

          dsx1CurrentBESs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1CurrentEntry 9 }

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          dsx1CurrentDMs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in the current 15 minute
                      interval. noSuchInstance will be returned if no
                      data is available."
               ::= { dsx1CurrentEntry 10 }

          dsx1CurrentLCVs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Line Code Violations (LCVs)
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1CurrentEntry 11 }

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          -- The DS1 Interval Table
          dsx1IntervalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1IntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Interval Table contains various
                      statistics collected by each DS1 Interface over
                      the previous 24 hours of operation.  The past 24
                      hours are broken into 96 completed 15 minute
                      intervals."
               ::= { ds1 8 }

          dsx1IntervalEntry OBJECT-TYPE
               SYNTAX  Dsx1IntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Interval table."
               INDEX   { dsx1IntervalIndex, dsx1IntervalNumber }
               ::= { dsx1IntervalTable 1 }

          Dsx1IntervalEntry ::=
               SEQUENCE {
                   dsx1IntervalIndex             InterfaceIndex,
                   dsx1IntervalNumber            INTEGER,
                   dsx1IntervalESs               PerfIntervalCount,
                   dsx1IntervalSESs              PerfIntervalCount,
                   dsx1IntervalSEFSs             PerfIntervalCount,
                   dsx1IntervalUASs              PerfIntervalCount,
                   dsx1IntervalCSSs              PerfIntervalCount,
                   dsx1IntervalPCVs              PerfIntervalCount,
                   dsx1IntervalLESs              PerfIntervalCount,
                   dsx1IntervalBESs              PerfIntervalCount,
                   dsx1IntervalDMs               PerfIntervalCount,
                   dsx1IntervalLCVs              PerfIntervalCount,
                   dsx1IntervalValidData         TruthValue
          }

          dsx1IntervalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1

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                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is the same interface as identified by the
                      same value as a dsx1LineIndex object instance."
               ::= { dsx1IntervalEntry 1 }

          dsx1IntervalNumber OBJECT-TYPE
               SYNTAX  INTEGER (1..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "A number between 1 and 96, where 1 is the most
                      recently completed 15 minute interval and 96 is
                      the 15 minutes interval completed 23 hours and 45
                      minutes prior to interval 1."
               ::= { dsx1IntervalEntry 2 }

          dsx1IntervalESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Errored Seconds encountered by a
                      DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1IntervalEntry 3 }

          dsx1IntervalSESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Seconds
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1IntervalEntry 4 }

          dsx1IntervalSEFSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current

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               DESCRIPTION
                      "The number of Severely Errored Framing Seconds
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals.  In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1IntervalEntry 5 }

          dsx1IntervalUASs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance.  This object may
                      decrease if the occurance of unavailable seconds
                      occurs across an inteval boundary."
               ::= { dsx1IntervalEntry 6 }

          dsx1IntervalCSSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Controlled Slip Seconds encountered
                      by a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1IntervalEntry 7 }

          dsx1IntervalPCVs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Path Coding Violations encountered
                      by a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1IntervalEntry 8 }

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          dsx1IntervalLESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Line Errored Seconds encountered by
                      a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1IntervalEntry 9 }

          dsx1IntervalBESs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1IntervalEntry 10 }

          dsx1IntervalDMs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1IntervalEntry 11 }

          dsx1IntervalLCVs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Line Code Violations (LCVs)
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data

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                      is not available, return noSuchInstance."
               ::= { dsx1IntervalEntry 12 }

          dsx1IntervalValidData OBJECT-TYPE
               SYNTAX TruthValue
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "This variable indicates if there is valid data
                      for this interval."
               ::= { dsx1IntervalEntry 13 }

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          -- The DS1 Total Table
          dsx1TotalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1TotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Total Table contains the cumulative sum
                      of the various statistics for the 24 hour period
                      preceding the current interval."
               ::= { ds1 9 }

          dsx1TotalEntry OBJECT-TYPE
               SYNTAX  Dsx1TotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Total table."
               INDEX   { dsx1TotalIndex }
               ::= { dsx1TotalTable 1 }

          Dsx1TotalEntry ::=
               SEQUENCE {
                   dsx1TotalIndex                InterfaceIndex,
                   dsx1TotalESs                  PerfTotalCount,
                   dsx1TotalSESs                 PerfTotalCount,
                   dsx1TotalSEFSs                PerfTotalCount,
                   dsx1TotalUASs                 PerfTotalCount,
                   dsx1TotalCSSs                 PerfTotalCount,
                   dsx1TotalPCVs                 PerfTotalCount,
                   dsx1TotalLESs                 PerfTotalCount,
                   dsx1TotalBESs                 PerfTotalCount,
                   dsx1TotalDMs                  PerfTotalCount,
                   dsx1TotalLCVs                 PerfTotalCount
          }

          dsx1TotalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is the same interface as identified by the
                      same value as a dsx1LineIndex object instance."

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               ::= { dsx1TotalEntry 1 }

          dsx1TotalESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The sum of Errored Seconds encountered by a DS1
                      interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1TotalEntry 2 }

          dsx1TotalSESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1TotalEntry 3 }

          dsx1TotalSEFSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Framing Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1TotalEntry 4 }

          dsx1TotalUASs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1TotalEntry 5 }

          dsx1TotalCSSs OBJECT-TYPE

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               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Controlled Slip Seconds encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1TotalEntry 6 }

          dsx1TotalPCVs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Path Coding Violations encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1TotalEntry 7 }

          dsx1TotalLESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Line Errored Seconds encountered by
                      a DS1 interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1TotalEntry 8 }

          dsx1TotalBESs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in the previous 24
                      hour interval. Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1TotalEntry 9 }

          dsx1TotalDMs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only

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               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1TotalEntry 10 }

          dsx1TotalLCVs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Line Code Violations (LCVs)
                      encountered by a DS1 interface in the current 15
                      minute interval.  Invalid 15 minute intervals
                      count as 0."
               ::= { dsx1TotalEntry 11 }

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          -- The DS1 Channel Table
          dsx1ChanMappingTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1ChanMappingEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Channel Mapping table.  This table maps a
                      DS1 channel number on a particular DS3 into an
                      ifIndex.  In the presence of DS2s, this table can
                      be used to map a DS2 channel number on a DS3 into
                      an ifIndex, or used to map a DS1 channel number on
                      a DS2 onto an ifIndex."
               ::= { ds1 16 }

          dsx1ChanMappingEntry OBJECT-TYPE
               SYNTAX  Dsx1ChanMappingEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Channel Mapping table.  There
                      is an entry in this table corresponding to each
                      ds1 ifEntry within any interface that is
                      channelized to the individual ds1 ifEntry level.

                      This table is intended to facilitate mapping from
                      channelized interface / channel number to DS1
                      ifEntry.  (e.g. mapping (DS3 ifIndex, DS1 Channel
                      Number) -> ifIndex)

                      While this table provides information that can
                      also be found in the ifStackTable and
                      dsx1ConfigTable, it provides this same information
                      with a single table lookup, rather than by walking
                      the ifStackTable to find the various constituent
                      ds1 ifTable entries, and testing various
                      dsx1ConfigTable entries to check for the entry
                      with the applicable DS1 channel number."
               INDEX   { ifIndex, dsx1Ds1ChannelNumber }
               ::= { dsx1ChanMappingTable 1 }

          Dsx1ChanMappingEntry ::=
               SEQUENCE {
                   dsx1ChanMappedIfIndex  InterfaceIndex
          }

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          dsx1ChanMappedIfIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "This object indicates the ifIndex value assigned
                      by the agent for the individual ds1 ifEntry that
                      corresponds to the given DS1 channel number
                      (specified by the INDEX element
                      dsx1Ds1ChannelNumber) of the given channelized
                      interface (specified by INDEX element ifIndex)."
               ::= { dsx1ChanMappingEntry 1 }

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          -- The DS1 Far End Current Table

          dsx1FarEndCurrentTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FarEndCurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Far End Current table contains various
                      statistics being collected for the current 15
                      minute interval.  The statistics are collected
                      from the far end messages on the Facilities Data
                      Link.  The definitions are the same as described
                      for the near-end information."
               ::= { ds1 10 }

          dsx1FarEndCurrentEntry OBJECT-TYPE
               SYNTAX  Dsx1FarEndCurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Far End Current table."
               INDEX   { dsx1FarEndCurrentIndex }
               ::= { dsx1FarEndCurrentTable 1 }

          Dsx1FarEndCurrentEntry ::=
               SEQUENCE {
                   dsx1FarEndCurrentIndex      InterfaceIndex,
                   dsx1FarEndTimeElapsed       INTEGER,
                   dsx1FarEndValidIntervals    INTEGER,
                   dsx1FarEndCurrentESs        PerfCurrentCount,
                   dsx1FarEndCurrentSESs       PerfCurrentCount,
                   dsx1FarEndCurrentSEFSs      PerfCurrentCount,
                   dsx1FarEndCurrentUASs       PerfCurrentCount,
                   dsx1FarEndCurrentCSSs       PerfCurrentCount,
                   dsx1FarEndCurrentLESs       PerfCurrentCount,
                   dsx1FarEndCurrentPCVs       PerfCurrentCount,
                   dsx1FarEndCurrentBESs       PerfCurrentCount,
                   dsx1FarEndCurrentDMs        PerfCurrentCount,
                   dsx1FarEndInvalidIntervals  INTEGER
          }

          dsx1FarEndCurrentIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current

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               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is identical to the interface identified by
                      the same value of dsx1LineIndex."
               ::= { dsx1FarEndCurrentEntry 1 }

          dsx1FarEndTimeElapsed OBJECT-TYPE
               SYNTAX  INTEGER (0..899)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of seconds that have elapsed since the
                      beginning of the far end current error-measurement
                      period."
               ::= { dsx1FarEndCurrentEntry 2 }

          dsx1FarEndValidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of previous far end intervals for
                      which valid data was collected.  The value will be
                      96 unless the interface was brought online within
                      the last 24 hours, in which case the value will be
                      the number of complete 15 minute far end intervals
                      since the interface has been online."
               ::= { dsx1FarEndCurrentEntry 3 }

          dsx1FarEndCurrentESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far Far End Errored Seconds
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1FarEndCurrentEntry 4 }

          dsx1FarEndCurrentSESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only

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               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Seconds
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1FarEndCurrentEntry 5 }

          dsx1FarEndCurrentSEFSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Framing
                      Seconds encountered by a DS1 interface in the
                      current 15 minute interval. noSuchInstance will be
                      returned if no data is available."
               ::= { dsx1FarEndCurrentEntry 6 }

          dsx1FarEndCurrentUASs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in the current 15 minute interval.
                      noSuchInstance will be returned if no data is
                      available."
               ::= { dsx1FarEndCurrentEntry 7 }

          dsx1FarEndCurrentCSSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Controlled Slip Seconds
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1FarEndCurrentEntry 8 }

          dsx1FarEndCurrentLESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current

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               DESCRIPTION
                      "The number of Far End Line Errored Seconds
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1FarEndCurrentEntry 9 }

          dsx1FarEndCurrentPCVs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Path Coding Violations
                      reported via the far end block error count
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1FarEndCurrentEntry 10 }

          dsx1FarEndCurrentBESs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in the current 15
                      minute interval. noSuchInstance will be returned
                      if no data is available."
               ::= { dsx1FarEndCurrentEntry 11 }

          dsx1FarEndCurrentDMs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in the current 15 minute
                      interval. noSuchInstance will be returned if no
                      data is available."
               ::= { dsx1FarEndCurrentEntry 12 }

          dsx1FarEndInvalidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current

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               DESCRIPTION
                      "The number of intervals for which no valid data
                      is available."
               ::= { dsx1FarEndCurrentEntry 13 }

          -- The DS1 Far End Interval Table
          dsx1FarEndIntervalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FarEndIntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Far End Interval Table contains various
                      statistics collected by each DS1 interface over
                      the previous 24 hours of operation.  The past 24
                      hours are broken into 96 completed 15 minute
                      intervals."
               ::= { ds1 11 }

          dsx1FarEndIntervalEntry OBJECT-TYPE
               SYNTAX  Dsx1FarEndIntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Far End Interval table."
               INDEX   { dsx1FarEndIntervalIndex,
                         dsx1FarEndIntervalNumber }
               ::= { dsx1FarEndIntervalTable 1 }

          Dsx1FarEndIntervalEntry ::=
               SEQUENCE {
                   dsx1FarEndIntervalIndex       InterfaceIndex,
                   dsx1FarEndIntervalNumber      INTEGER,
                   dsx1FarEndIntervalESs         PerfIntervalCount,
                   dsx1FarEndIntervalSESs        PerfIntervalCount,
                   dsx1FarEndIntervalSEFSs       PerfIntervalCount,
                   dsx1FarEndIntervalUASs        PerfIntervalCount,
                   dsx1FarEndIntervalCSSs        PerfIntervalCount,
                   dsx1FarEndIntervalLESs        PerfIntervalCount,
                   dsx1FarEndIntervalPCVs        PerfIntervalCount,
                   dsx1FarEndIntervalBESs        PerfIntervalCount,
                   dsx1FarEndIntervalDMs         PerfIntervalCount,
                   dsx1FarEndIntervalValidData   TruthValue
          }

          dsx1FarEndIntervalIndex OBJECT-TYPE

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               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is identical to the interface identified by
                      the same value of dsx1LineIndex."
               ::= { dsx1FarEndIntervalEntry 1 }

          dsx1FarEndIntervalNumber OBJECT-TYPE
               SYNTAX  INTEGER (1..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "A number between 1 and 96, where 1 is the most
                      recently completed 15 minute interval and 96 is
                      the 15 minutes interval completed 23 hours and 45
                      minutes prior to interval 1."
               ::= { dsx1FarEndIntervalEntry 2 }

          dsx1FarEndIntervalESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Errored Seconds encountered
                      by a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 3 }

          dsx1FarEndIntervalSESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Seconds
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 4 }

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          dsx1FarEndIntervalSEFSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Framing
                      Seconds encountered by a DS1 interface in one of
                      the previous 96, individual 15 minute, intervals.
                      In the case where the agent is a proxy and valid
                      data is not available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 5 }

          dsx1FarEndIntervalUASs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 6 }

          dsx1FarEndIntervalCSSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Controlled Slip Seconds
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 7 }

          dsx1FarEndIntervalLESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Line Errored Seconds
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data

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                      is not available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 8 }

          dsx1FarEndIntervalPCVs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Path Coding Violations
                      reported via the far end block error count
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 9 }

          dsx1FarEndIntervalBESs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in one of the
                      previous 96, individual 15 minute, intervals. In
                      the case where the agent is a proxy and valid data
                      is not available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 10 }

          dsx1FarEndIntervalDMs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in one of the previous 96,
                      individual 15 minute, intervals. In the case where
                      the agent is a proxy and valid data is not
                      available, return noSuchInstance."
               ::= { dsx1FarEndIntervalEntry 11 }

          dsx1FarEndIntervalValidData OBJECT-TYPE
               SYNTAX TruthValue
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION

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                      "This variable indicates if there is valid data
                      for this interval."
               ::= { dsx1FarEndIntervalEntry 12 }

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          -- The DS1 Far End Total Table

          dsx1FarEndTotalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FarEndTotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Far End Total Table contains the
                      cumulative sum of the various statistics for the
                      24 hour period preceding the current interval."
               ::= { ds1 12 }

          dsx1FarEndTotalEntry OBJECT-TYPE
               SYNTAX  Dsx1FarEndTotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Far End Total table."
               INDEX   { dsx1FarEndTotalIndex }
               ::= { dsx1FarEndTotalTable 1 }

          Dsx1FarEndTotalEntry ::=
               SEQUENCE {
                   dsx1FarEndTotalIndex          InterfaceIndex,
                   dsx1FarEndTotalESs            PerfTotalCount,
                   dsx1FarEndTotalSESs           PerfTotalCount,
                   dsx1FarEndTotalSEFSs          PerfTotalCount,
                   dsx1FarEndTotalUASs           PerfTotalCount,
                   dsx1FarEndTotalCSSs           PerfTotalCount,
                   dsx1FarEndTotalLESs           PerfTotalCount,
                   dsx1FarEndTotalPCVs           PerfTotalCount,
                   dsx1FarEndTotalBESs           PerfTotalCount,
                   dsx1FarEndTotalDMs            PerfTotalCount
          }

          dsx1FarEndTotalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is identical to the interface identified by
                      the same value of dsx1LineIndex."

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               ::= { dsx1FarEndTotalEntry 1 }

          dsx1FarEndTotalESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Errored Seconds encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1FarEndTotalEntry 2 }

          dsx1FarEndTotalSESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 3 }

          dsx1FarEndTotalSEFSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Framing
                      Seconds encountered by a DS1 interface in the
                      previous 24 hour interval. Invalid 15 minute
                      intervals count as 0."
               ::= { dsx1FarEndTotalEntry 4 }

          dsx1FarEndTotalUASs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1FarEndTotalEntry 5 }

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          dsx1FarEndTotalCSSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Controlled Slip Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 6 }

          dsx1FarEndTotalLESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Line Errored Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 7 }

          dsx1FarEndTotalPCVs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Path Coding Violations
                      reported via the far end block error count
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 8 }

          dsx1FarEndTotalBESs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in the previous 24
                      hour interval. Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 9 }

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          dsx1FarEndTotalDMs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1FarEndTotalEntry 10 }

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          -- The DS1 Fractional Table
          dsx1FracTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FracEntry
               MAX-ACCESS  not-accessible
               STATUS  deprecated
               DESCRIPTION
                      "This table is deprecated in favour of using
                      ifStackTable.

                      The table was mandatory for systems dividing a DS1
                      into channels containing different data streams
                      that are of local interest.  Systems which are
                      indifferent to data content, such as CSUs, need
                      not implement it.

                      The DS1 fractional table identifies which DS1
                      channels associated with a CSU are being used to
                      support a logical interface, i.e., an entry in the
                      interfaces table from the Internet-standard MIB.

                      For example, consider an application managing a
                      North American ISDN Primary Rate link whose
                      division is a 384 kbit/s H1 _B_ Channel for Video,
                      a second H1 for data to a primary routing peer,
                      and 12 64 kbit/s H0 _B_ Channels. Consider that
                      some subset of the H0 channels are used for voice
                      and the remainder are available for dynamic data
                      calls.

                      We count a total of 14 interfaces multiplexed onto
                      the DS1 interface. Six DS1 channels (for the sake
                      of the example, channels 1..6) are used for Video,
                      six more (7..11 and 13) are used for data, and the
                      remaining 12 are are in channels 12 and 14..24.

                      Let us further imagine that ifIndex 2 is of type
                      DS1 and refers to the DS1 interface, and that the
                      interfaces layered onto it are numbered 3..16.

                      We might describe the allocation of channels, in
                      the dsx1FracTable, as follows:
                    dsx1FracIfIndex.2. 1 = 3  dsx1FracIfIndex.2.13 = 4
                    dsx1FracIfIndex.2. 2 = 3  dsx1FracIfIndex.2.14 = 6
                    dsx1FracIfIndex.2. 3 = 3  dsx1FracIfIndex.2.15 = 7
                    dsx1FracIfIndex.2. 4 = 3  dsx1FracIfIndex.2.16 = 8

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                    dsx1FracIfIndex.2. 5 = 3  dsx1FracIfIndex.2.17 = 9
                    dsx1FracIfIndex.2. 6 = 3  dsx1FracIfIndex.2.18 = 10
                    dsx1FracIfIndex.2. 7 = 4  dsx1FracIfIndex.2.19 = 11
                    dsx1FracIfIndex.2. 8 = 4  dsx1FracIfIndex.2.20 = 12
                    dsx1FracIfIndex.2. 9 = 4  dsx1FracIfIndex.2.21 = 13
                    dsx1FracIfIndex.2.10 = 4  dsx1FracIfIndex.2.22 = 14
                    dsx1FracIfIndex.2.11 = 4  dsx1FracIfIndex.2.23 = 15
                    dsx1FracIfIndex.2.12 = 5  dsx1FracIfIndex.2.24 = 16

                      For North American (DS1) interfaces, there are 24
                      legal channels, numbered 1 through 24.

                      For G.704 interfaces, there are 31 legal channels,
                      numbered 1 through 31.  The channels (1..31)
                      correspond directly to the equivalently numbered
                      time-slots."
               ::= { ds1 13 }

          dsx1FracEntry OBJECT-TYPE
               SYNTAX  Dsx1FracEntry
               MAX-ACCESS  not-accessible
               STATUS  deprecated
               DESCRIPTION
                  "An entry in the DS1 Fractional table."
              INDEX   { dsx1FracIndex, dsx1FracNumber }
              ::= { dsx1FracTable 1 }

          Dsx1FracEntry ::=
              SEQUENCE {
                  dsx1FracIndex        INTEGER,
                  dsx1FracNumber       INTEGER,
                  dsx1FracIfIndex      INTEGER
              }

          dsx1FracIndex OBJECT-TYPE
              SYNTAX  INTEGER (1..'7fffffff'h)
              MAX-ACCESS  read-only
              STATUS  deprecated
              DESCRIPTION
                 "The index value which uniquely identifies  the
                 DS1  interface  to which this entry is applicable
                 The interface identified by a  particular
                 value  of  this  index is the same interface as
                 identified by the same value  an  dsx1LineIndex

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                 object instance."
             ::= { dsx1FracEntry 1 }

          dsx1FracNumber OBJECT-TYPE
              SYNTAX  INTEGER (1..31)
              MAX-ACCESS  read-only
              STATUS  deprecated
              DESCRIPTION
                 "The channel number for this entry."
             ::= { dsx1FracEntry 2 }

          dsx1FracIfIndex OBJECT-TYPE
              SYNTAX  INTEGER (1..'7fffffff'h)
              MAX-ACCESS  read-write
              STATUS  deprecated
              DESCRIPTION
                 "An index value that uniquely identifies an
                 interface.  The interface identified by a particular
                 value of this index is the same  interface
                 as  identified by the same value an ifIndex
                 object instance. If no interface is currently using
                 a channel, the value should be zero.  If a
                 single interface occupies more  than  one  time
                 slot,  that ifIndex value will be found in multiple
                 time slots."
             ::= { dsx1FracEntry 3 }

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           -- Ds1 TRAPS

          ds1Traps OBJECT IDENTIFIER ::= { ds1 15 }

          dsx1LineStatusChange NOTIFICATION-TYPE
              OBJECTS { dsx1LineStatus,
                        dsx1LineStatusLastChange }
              STATUS  current
              DESCRIPTION
                      "A dsx1LineStatusChange trap is sent when the
                      value of an instance dsx1LineStatus changes. It
                      can be utilized by an NMS to trigger polls.  When
                      the line status change results from a higher level
                      line status change (i.e. ds3), then no traps for
                      the ds1 are sent."
               ::= { ds1Traps 0 1 }

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          -- conformance information
          ds1Conformance OBJECT IDENTIFIER ::= { ds1 14 }

          ds1Groups      OBJECT IDENTIFIER ::= { ds1Conformance 1 }
          ds1Compliances OBJECT IDENTIFIER ::= { ds1Conformance 2 }

          -- compliance statements

          ds1Compliance MODULE-COMPLIANCE
              STATUS  current
              DESCRIPTION
                      "The compliance statement for T1 and E1
                      interfaces."
              MODULE  -- this module
                  MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                     ds1NearEndStatisticsGroup }

                  GROUP       ds1FarEndGroup
                  DESCRIPTION
                      "Implementation of this group is optional for all
                      systems that attach to a DS1 Interface."

                  GROUP       ds1NearEndOptionalConfigGroup
                  DESCRIPTION
                      "Implementation of this group is optional for all
                      systems that attach to a DS1 Interface."

                  GROUP       ds1DS2Group
                  DESCRIPTION
                      "Implementation of this group is mandatory for all
                      systems that attach to a DS2 Interface."

                  GROUP       ds1TransStatsGroup
                  DESCRIPTION
                      "This group is the set of statistics appropriate
                      for all systems which attach to a DS1 Interface
                      running transparent or unFramed lineType."

                  GROUP       ds1ChanMappingGroup
                  DESCRIPTION
                      "This group is the set of objects for mapping a
                      DS3 Channel (ds1ChannelNumber) to ifIndex.

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                      Implementation of this group is mandatory for
                      systems which support the channelization of DS3s
                      into DS1s."

                  OBJECT dsx1LineType
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line type is not
                      required."

                  OBJECT dsx1LineCoding
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line coding is not
                      required."

                  OBJECT dsx1SendCode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the send code is not
                      required."

                  OBJECT dsx1LoopbackConfig
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set loopbacks is not required."

                  OBJECT dsx1SignalMode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the signal mode is not
                      required."

                  OBJECT dsx1TransmitClockSource
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the transmit clock source is
                      not required."

                  OBJECT dsx1Fdl
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the FDL is not required."

                  OBJECT dsx1LineLength

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                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line length is not
                      required."

                  OBJECT dsx1Channelization
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the channelization is not
                      required."
              ::= { ds1Compliances 1 }

          ds1MibT1PriCompliance MODULE-COMPLIANCE
              STATUS current
              DESCRIPTION
                      "Compliance statement for using this MIB for ISDN
                      Primary Rate interfaces on T1 lines."
              MODULE
                  MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                     ds1NearEndStatisticsGroup }
                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                          dsx1ESF(2)   -- Intl Spec would be G704(2)
                                       -- or I.431(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Line type for T1 ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1LineCoding
                      SYNTAX INTEGER {
                          dsx1B8ZS(2)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Type of Zero Code Suppression for
                           T1 ISDN Primary Rate interfaces."

                  OBJECT dsx1SignalMode
                      SYNTAX INTEGER {
                          none(1), -- if there is no signaling channel
                          messageOriented(4)
                      }
                      MIN-ACCESS read-only

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                      DESCRIPTION
                          "Possible signaling modes for
                           T1 ISDN Primary Rate interfaces."

                  OBJECT dsx1TransmitClockSource
                      SYNTAX INTEGER {
                          loopTiming(1)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The transmit clock is derived from
                           received clock on ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1Fdl
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Facilities Data Link usage on T1 ISDN
                           Primary Rate interfaces.
                           Note: Eventually dsx1Att-54016(4) is to be
                                 used here since the line type is ESF."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the channelization
                           is not required."
              ::= { ds1Compliances 2 }

          ds1MibE1PriCompliance MODULE-COMPLIANCE
              STATUS current
              DESCRIPTION
                      "Compliance statement for using this MIB for ISDN
                      Primary Rate interfaces on E1 lines."
              MODULE
                  MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                     ds1NearEndStatisticsGroup }
                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                          dsx1E1CRC(5)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Line type for E1 ISDN Primary Rate

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                           interfaces."

                  OBJECT dsx1LineCoding
                      SYNTAX INTEGER {
                          dsx1HDB3(3)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Type of Zero Code Suppression for
                           E1 ISDN Primary Rate interfaces."

                  OBJECT dsx1SignalMode
                      SYNTAX INTEGER {
                          messageOriented(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Signaling on E1 ISDN Primary Rate interfaces
                           is always message oriented."

                  OBJECT dsx1TransmitClockSource
                      SYNTAX INTEGER {
                          loopTiming(1)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The transmit clock is derived from received
                           clock on ISDN Primary Rate interfaces."

                  OBJECT dsx1Fdl
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Facilities Data Link usage on E1 ISDN
                           Primary Rate interfaces.
                           Note: There is a 'M-Channel' in E1,
                                 using National Bit Sa4 (G704,
                                 Table 4a). It is used to implement
                                 management features between ET
                                 and NT.  This is different to
                                 FDL in T1, which is used to carry
                                 control signals and performance
                                 data.  In E1, control and status
                                 signals are carried using National
                                 Bits Sa5, Sa6 and A (RAI Ind.).
                           This indicates that only the other(1) or

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                           eventually the dsx1Fdl-none(8) bits should
                           be set in this object for E1 PRI."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                      "The ability to set the channelization is not
                      required."
              ::= { ds1Compliances 3 }

          ds1Ds2Compliance MODULE-COMPLIANCE
              STATUS current
              DESCRIPTION
                      "Compliance statement for using this MIB for DS2
                      interfaces."
              MODULE
                  MANDATORY-GROUPS { ds1DS2Group }

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                      "The ability to set the channelization is not
                      required."
              ::= { ds1Compliances 4 }

          -- units of conformance

          ds1NearEndConfigGroup  OBJECT-GROUP
              OBJECTS { dsx1LineIndex,
                        dsx1TimeElapsed,
                        dsx1ValidIntervals,
                        dsx1LineType,
                        dsx1LineCoding,
                        dsx1SendCode,
                        dsx1CircuitIdentifier,
                        dsx1LoopbackConfig,
                        dsx1LineStatus,
                        dsx1SignalMode,
                        dsx1TransmitClockSource,
                        dsx1Fdl,
                        dsx1InvalidIntervals,
                        dsx1LineLength,
                        dsx1LoopbackStatus,
                        dsx1Ds1ChannelNumber,

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                        dsx1Channelization }
              STATUS  current
              DESCRIPTION
                      "A collection of objects providing configuration
                      information applicable to all DS1 interfaces."
              ::= { ds1Groups 1 }

          ds1NearEndStatisticsGroup OBJECT-GROUP
              OBJECTS { dsx1CurrentIndex,
                        dsx1CurrentESs,
                        dsx1CurrentSESs,
                        dsx1CurrentSEFSs,
                        dsx1CurrentUASs,
                        dsx1CurrentCSSs,
                        dsx1CurrentPCVs,
                        dsx1CurrentLESs,
                        dsx1CurrentBESs,
                        dsx1CurrentDMs,
                        dsx1CurrentLCVs,
                        dsx1IntervalIndex,
                        dsx1IntervalNumber,
                        dsx1IntervalESs,
                        dsx1IntervalSESs,
                        dsx1IntervalSEFSs,
                        dsx1IntervalUASs,
                        dsx1IntervalCSSs,
                        dsx1IntervalPCVs,
                        dsx1IntervalLESs,
                        dsx1IntervalBESs,
                        dsx1IntervalDMs,
                        dsx1IntervalLCVs,
                        dsx1IntervalValidData,
                        dsx1TotalIndex,
                        dsx1TotalESs,
                        dsx1TotalSESs,
                        dsx1TotalSEFSs,
                        dsx1TotalUASs,
                        dsx1TotalCSSs,
                        dsx1TotalPCVs,
                        dsx1TotalLESs,
                        dsx1TotalBESs,
                        dsx1TotalDMs,
                        dsx1TotalLCVs }
              STATUS  current
              DESCRIPTION

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                      "A collection of objects providing statistics
                      information applicable to all DS1 interfaces."
              ::= { ds1Groups 2 }

          ds1FarEndGroup  OBJECT-GROUP
              OBJECTS { dsx1FarEndCurrentIndex,
                        dsx1FarEndTimeElapsed,
                        dsx1FarEndValidIntervals,
                        dsx1FarEndCurrentESs,
                        dsx1FarEndCurrentSESs,
                        dsx1FarEndCurrentSEFSs,
                        dsx1FarEndCurrentUASs,
                        dsx1FarEndCurrentCSSs,
                        dsx1FarEndCurrentLESs,
                        dsx1FarEndCurrentPCVs,
                        dsx1FarEndCurrentBESs,
                        dsx1FarEndCurrentDMs,
                        dsx1FarEndInvalidIntervals,
                        dsx1FarEndIntervalIndex,
                        dsx1FarEndIntervalNumber,
                        dsx1FarEndIntervalESs,
                        dsx1FarEndIntervalSESs,
                        dsx1FarEndIntervalSEFSs,
                        dsx1FarEndIntervalUASs,
                        dsx1FarEndIntervalCSSs,
                        dsx1FarEndIntervalLESs,
                        dsx1FarEndIntervalPCVs,
                        dsx1FarEndIntervalBESs,
                        dsx1FarEndIntervalDMs,
                        dsx1FarEndIntervalValidData,
                        dsx1FarEndTotalIndex,
                        dsx1FarEndTotalESs,
                        dsx1FarEndTotalSESs,
                        dsx1FarEndTotalSEFSs,
                        dsx1FarEndTotalUASs,
                        dsx1FarEndTotalCSSs,
                        dsx1FarEndTotalLESs,
                        dsx1FarEndTotalPCVs,
                        dsx1FarEndTotalBESs,
                        dsx1FarEndTotalDMs }
              STATUS  current
              DESCRIPTION
                      "A collection of objects providing remote
                      configuration and statistics information."
              ::= { ds1Groups 3 }

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          ds1DeprecatedGroup OBJECT-GROUP
              OBJECTS { dsx1IfIndex,
                        dsx1FracIndex,
                        dsx1FracNumber,
                        dsx1FracIfIndex }
              STATUS  deprecated
              DESCRIPTION
                      "A collection of obsolete objects that may be
                      implemented for backwards compatibility."
              ::= { ds1Groups 4 }

          ds1NearEndOptionalConfigGroup OBJECT-GROUP
              OBJECTS { dsx1LineStatusLastChange,
                        dsx1LineStatusChangeTrapEnable }

              STATUS    current
              DESCRIPTION
                      "A collection of objects that may be implemented
                      on DS1 and DS2 interfaces."
              ::= { ds1Groups 5 }

          ds1DS2Group OBJECT-GROUP
              OBJECTS { dsx1LineIndex,
                        dsx1LineType,
                        dsx1LineCoding,
                        dsx1SendCode,
                        dsx1LineStatus,
                        dsx1SignalMode,
                        dsx1TransmitClockSource,
                        dsx1Channelization }
              STATUS   current
              DESCRIPTION
                      "A collection of objects providing information
                      about DS2 (6,312 kbps) and E2 (8,448 kbps)
                      systems."
              ::= { ds1Groups 6 }

          ds1TransStatsGroup OBJECT-GROUP
              OBJECTS { dsx1CurrentESs,
                        dsx1CurrentSESs,
                        dsx1CurrentUASs,
                        dsx1IntervalESs,
                        dsx1IntervalSESs,
                        dsx1IntervalUASs,
                        dsx1TotalESs,

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                        dsx1TotalSESs,
                        dsx1TotalUASs }
              STATUS   current
              DESCRIPTION
                           "A collection of objects which are the
                      statistics which can be collected from a ds1
                      interface that is running transparent or unframed
                      lineType.  Statistics not in this list should
                      return noSuchInstance."
              ::= { ds1Groups 7 }

          ds1NearEndOptionalTrapGroup NOTIFICATION-GROUP
              NOTIFICATIONS { dsx1LineStatusChange }
              STATUS    current
              DESCRIPTION
                      "A collection of notifications that may be
                      implemented on DS1 and DS2 interfaces."
              ::= { ds1Groups 8 }

          ds1ChanMappingGroup OBJECT-GROUP
              OBJECTS { dsx1ChanMappedIfIndex }
              STATUS    current
              DESCRIPTION
                      "A collection of objects that give an mapping of
                      DS3 Channel (ds1ChannelNumber) to ifIndex."
              ::= { ds1Groups 9 }

          END

5.  Appendix A - Use of dsx1IfIndex and dsx1LineIndex

   This Appendix exists to document the previous use if dsx1IfIndex and
   dsx1LineIndex and to clarify the relationship of dsx1LineIndex as
   defined in rfc1406 with the dsx1LineIndex as defined in this
   document.

   The following shows the old and new definitions and the relationship:

   [New Definition]: "This object should be made equal to ifIndex.  The
   next paragraph describes its previous usage.  Making the object equal
   to ifIndex allows proper use of ifStackTable and ds0/ds0bundle mibs.

   [Old Definition]: "This object is the identifier of a DS1 Interface
   on a managed device.  If there is an ifEntry that is directly
   associated with this and only this DS1 interface, it should have the

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   same value as ifIndex.  Otherwise, number the dsx1LineIndices with an
   unique identifier following the rules of choosing a number that is
   greater than ifNumber and numbering the inside interfaces (e.g.,
   equipment side) with even numbers and outside interfaces (e.g,
   network side) with odd numbers."

   When the "Old Definition" was created, it was described this way to
   allow a manager to treat the value _as if_ it were and ifIndex, i.e.
   the value would either be:  1) an ifIndex value or 2) a value that
   was guaranteed to be different from all valid ifIndex values.

   The new definition is a subset of that definition, i.e. the value is
   always an ifIndex value.

   The following is Section 3.1 from rfc1406:

   Different physical configurations for the support of SNMP with DS1
   equipment exist. To accommodate these scenarios, two different
   indices for DS1 interfaces are introduced in this MIB.  These indices
   are dsx1IfIndex and dsx1LineIndex.

   External interface scenario: the SNMP Agent represents all managed
   DS1 lines as external interfaces (for example, an Agent residing on
   the device supporting DS1 interfaces directly):

   For this scenario, all interfaces are assigned an integer value equal
   to ifIndex, and the following applies:

      ifIndex=dsx1IfIndex=dsx1LineIndex for all interfaces.

   The dsx1IfIndex column of the DS1 Configuration table relates each
   DS1 interface to its corresponding interface (ifIndex) in the
   Internet-standard MIB (MIB-II STD 17, RFC1213).

   External&Internal interface scenario: the SNMP Agents resides on an
   host external from the device supporting DS1 interfaces (e.g., a
   router). The Agent represents both the host and the DS1 device.  The
   index dsx1LineIndex is used to not only represent the DS1 interfaces
   external from the host/DS1-device combination, but also the DS1
   interfaces connecting the host and the DS1 device.  The index
   dsx1IfIndex is always equal to ifIndex.

   Example:

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   A shelf full of CSUs connected to a Router. An SNMP Agent residing on
   the router proxies for itself and the CSU. The router has also an
   Ethernet interface:

         +-----+
   |     |     |
   |     |     |               +---------------------+
   |E    |     |  1.544  MBPS  |              Line#A | DS1 Link
   |t    |  R  |---------------+ - - - - -  - - -  - +------>
   |h    |     |               |                     |
   |e    |  O  |  1.544  MBPS  |              Line#B | DS1 Link
   |r    |     |---------------+ - - - - - - - - - - +------>
   |n    |  U  |               |  CSU Shelf          |
   |e    |     |  1.544  MBPS  |              Line#C | DS1 Link
   |t    |  T  |---------------+ - - - -- -- - - - - +------>
   |     |     |               |                     |
   |-----|  E  |  1.544  MBPS  |              Line#D | DS1 Link
   |     |     |---------------+ -  - - - -- - - - - +------>
   |     |  R  |               |_____________________|
   |     |     |
   |     +-----+

   The assignment of the index values could for example be:

           ifIndex (= dsx1IfIndex)                     dsx1LineIndex
                   1                   NA                  NA (Ethernet)
                   2      Line#A   Router Side             6
                   2      Line#A   Network Side            7
                   3      Line#B   Router Side             8
                   3      Line#B   Network Side            9
                   4      Line#C   Router Side            10
                   4      Line#C   Network Side           11
                   5      Line#D   Router Side            12
                   5      Line#D   Network Side           13

   For this example, ifNumber is equal to 5.  Note the following
   description of dsx1LineIndex:  the dsx1LineIndex identifies a DS1
   Interface on a managed device.  If there is an ifEntry that is
   directly associated with this and only this DS1 interface, it should
   have the same value as ifIndex.  Otherwise, number the
   dsx1LineIndices with an unique identifier following the rules of
   choosing a number greater than ifNumber and numbering inside
   interfaces (e.g., equipment side) with even numbers and outside
   interfaces (e.g., network side) with odd numbers.

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   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be:

           ifIndex (= dsx1IfIndex)                      dsx1LineIndex
                   1      Line#A     Network Side            1
                   2      Line#A     RouterSide              2
                   3      Line#B     Network Side            3
                   4      Line#B     RouterSide              4
                   5      Line#C     Network Side            5
                   6      Line#C     Router Side             6
                   7      Line#D     Network Side            7
                   8      Line#D     Router Side             8

6.  Appendix B - The delay approach to Unavialable Seconds.

   This procedure is illustrated below for a DS1 ESF interface.  Similar
   rules would apply for other DS1, DS2, and E1 interface variants.  The
   procedure guarantees that the statistical counters are correctly
   updated at all times, although they lag real time by 10 seconds.  At
   the end of each 15 minutes interval the current interval counts are
   transferred to the  most recent interval entry and each interval is
   shifted up by one position, with the oldest being discarded if
   necessary in order to make room.  The current interval counts then
   start over from zero.  Note, however, that the signal state
   calculation does not start afresh at each interval boundary;  rather,
   signal state information is retained across interval boundaries.
+---------------------------------------------------------------------+
|               READ COUNTERS & STATUS INFO FROM HARDWARE             |
|                                                                     |
| BPV EXZ LOS FE CRC CS AIS SEF OOF LOF       RAI G1-G6 SE FE LV SL   |
+---------------------------------------------------------------------+
   |   |   |   |  |   |  |   |   |   |         |    |    |  |  |  |
   |   |   |   |  |   |  |   |   |   |         |    |    |  |  |  |
   V   V   V   V  V   V  V   V   V   V         V    V    V  V  V  V
+---------------------------------------------------------------------+
|    ACCUM ONE-SEC STATS, CHK ERR THRESHOLDS, & UPDT SIGNAL STATE     |
|                                                                     |
|  |<---------- NEAR END ----------->|    |<-------- FAR END ------>| |
|                                                                     |
|  LCV LES PCV ES CSS BES SES SEFS A/U    PCV ES CSS BES SES SEFS A/U |
+---------------------------------------------------------------------+
    |   |   |  |   |   |   |   |    |      |  |   |   |   |   |    |
    |   |   |  |   |   |   |   |    |      |  |   |   |   |   |    |
    V   V   V  V   V   V   V   V    |      V  V   V   V   V   V    |
 +------------------------------+   |    +----------------------+  |

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 |         ONE-SEC DELAY        |   |    |    ONE-SEC DELAY     |  |
 |           (1 OF 10)          |   |    |      (1 OF 10)       |  |
 +------------------------------+   |    +----------------------+  |
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   /   /   /  /   /   /   /   /     /      /  /   /   /   /   /    /
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   V   V   V  V   V   V   V   V     |      V  V   V   V   V   V    |
 +------------------------------+   |    +----------------------+  |
 |         ONE-SEC DELAY        |   |    |    ONE-SEC DELAY     |  |
 |           (10 OF 10)         |   |    |      (10 OF 10)      |  |
 +------------------------------+   |    +----------------------+  |
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   V   V   V  V   V   V   V   V     V      V  V   V   V   V   V    V
+---------------------------------------------------------------------+
|                    UPDATE STATISTICS COUNTERS                       |
|                                                                     |
|<-------------- NEAR END ----------->| |<--------- FAR END --------->|
|                                                                     |
|LCV LES PCV ES CSS BES SES SEFS UAS DM PCV ES CSS BES SES SEFS UAS DM|
+---------------------------------------------------------------------+

   Note that if such a procedure is adopted there is no current interval
   data for the first ten seconds after a system comes up.
   noSuchInstance must be returned if a management station attempts to
   access the current interval counters during this time.

   It is an implementation-specific matter whether an agent assumes that
   the initial state of the interface is available or unavailable.

7.  Acknowledgments

   This document was produced by the Trunk MIB Working Group

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8.  References

   [1] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
       S. Waldbusser, "Structure of Management Information for Version 2
       of the Simple Network Management Protocol (SNMPv2)", RFC 1902,
       January 1996.

   [2] McCloghrie, K., and M. Rose, Editors, "Management
       Information Base for Network Management of TCP/IP-based
       internets: MIB-II", STD 17, RFC 1213, Hughes LAN Systems,
       Performance Systems International, March 1991.

   [3] Case, J., Fedor, M., Schoffstall, M., and J. Davin. " A Simple
       Network Management Protocol (SNMP)", STD 15, RFC 1157, SNMP
       Research, Performance Systems International, MIT Lab for
       Computer Science, May 1990.

   [4] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and
       S. Waldbusser, "Protocol Operations for Version 2 of the Simple
       Network Management Protocol (SNMPv2)", RFC 1905, January 1996.

   [5] McCloghrie, K. and F. Kastenholz, "Evolution of the
       Interfaces Group of MIB-II", RFC 1573, Hughes LAN
       Systems, FTP Software, January 1994.

   [6] AT&T Information Systems, AT&T ESF DS1 Channel Service Unit
       User's Manual, 999-100-305, February 1988.

   [7] AT&T Technical Reference, Requirements for Interfacing Digital
       Terminal Equipment to Services Employing the Extended Superframe
       Format, Publication 54016, May 1988.

   [8] American National Standard for Telecommunications -- Carrier-to-
       Customer Installation - DS1 Metallic Interface, T1.403, February
       1989.

   [9] CCITT Specifications Volume III, Recommendation G.703,
       Physical/Electrical Characteristics of Hierarchical Digital
       Interfaces, April 1991.

   [10] ITU-T G.704: Synchronous frame structures used at 1544, 6312,
        2048, 8488 and 44 736 kbit/s Hierarchical Levels, July 1995.

  [11] American National Standard for Telecommunications -- Digital
       Hierarchy -- Layer 1 In-Service Digital Transmission

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       Performace Monitoring, T1.231, Sept 1993.

  [12] CCITT Specifications Volume IV, Recommendation O.162, Equipment
       To Perform In Service Monitoring On 2048 kbit/s Signals, July
       1988

  [13] CCITT Specifications Volume III, Recommendation G.821, Error
       Performance Of An International Digital Connection Forming Part
       Of An Integrated Services Digital Network, July 1988.

  [14] AT&T Technical Reference, Technical Reference 62411, ACCUNET T1.5
       Service Description And Interface Specification, December 1990.

  [15] CCITT Specifications Volume III, Recommendation G.706, Frame
       Alignment and Cyclic Redundancy Check (CRC) Procedures Relating
       to Basic Frame Structures Defined in Recommendation G.704, July
       1988.

  [16] CCITT Specifications Volume III, Recommendation G.732,
       Characteristics Of Primary PCM Multiplex Equipment Operating at
       2048 kbit/s, July 1988.

  [17] Fowler, D., "Definitions of Managed Objects for the DS3/E3
       Interface Types", draft-ietf-trunkmib-ds3-mib-02.txt,
       Newbridge Networks, February 1996

  [18] Brown, T., and Tesink, K., "Definitions of Managed Objects
       for the SONET/SDH Interface Type", RFC1595, Bell Communications
       Research, March 1994.

  [19] Fowler, D., "Definitions of Managed Objects for the Ds0 and
       DS0Bundle Interface Types", draft-ietf-trunkmib-ds0-mib-02.txt,
       Newbridge Networks, March 1996.

  [20] ITU-T G.775: Loss of signal (LOS) and alarm indication
       signal (AIS) defect detection and clearance criteria, May 1995.

  [21] McCloghrie, K. and F. Kastenholz, "Evolution of the
       Interfaces Group of MIB-II", draft-ietf-ifmib-mib-03.txt,
       Cisco, FTP Software, January 1994.

  [22] ITU-T G.826: Error performance parameters and objectives for
       international, constant bit rate digital paths at or above
       the primary rate, November 1993.

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  [23] American National Standard for Telecommunications -- Digital
       Hierarchy - Electrical Interfaces, T1.102, December 1993.

  [24] American National Standard for Telecommunications -- Digital
       Hierarchy - Format Specifications, T1.107, August 1988.

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9.  Security Considerations

   This MIB adds no security issues that are not raised by SNMP itself.
   As a Network Management Protocol, SNMP is capable of changing the
   configuration of a system, of denial of service attacks through
   requiring the agent to respond to its messages, and displaying values
   of system counters and configuration settings in the clear where an
   adversary might read them. This, however, is not in itself a threat:
   this is the function of the protocol, but could be misused. Such
   misuse can be avoided or minimized through SNMP Security.

   Setting any of the following objects to an inappropriate value can
   cause loss of traffic.  The definition of inappropriate varies for
   each object.  In the case of dsx1LineType, for example, both ends of
   a ds1/e1 must have the same value in order for traffic to flow.  In
   the case of dsx1SendCode and dsx1LoopbackConfig, for another example,
   traffic may stop transmitting when particular loopbacks are applied.
      dsx1LineType
      dsx1LineCoding
      dsx1SendCode
      dsx1LoopbackConfig
      dsx1SignalMode
      dsx1TransmitClockSource
      dsx1Fdl
      dsx1LineLength
      dsx1Channelization

   Setting the following object is mischevious, but not harmful to
   traffic
      dsx1CircuitIdentifier

   Setting the following object can cause an increase in the number of
   traps received by the network management station.
      dsx1LineStatusChangeTrabEnable

10.  Author's Address

      David Fowler
      Newbridge Networks
      600 March Road
      Kanata, Ontario, Canada K2K 2E6

      Phone: (613) 599-3600, ext 6559

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      EMail: [email-masked]

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INTERNET-DRAFT             DS1/E1/DS2/E2 MIB               February 1998

   Table of Contents

   1 The SNMPv2 Network Management Framework ......................    2
   2 Object Definitions ...........................................    3
   2.1 Changes from RFC1406 .......................................    3
   3 Overview .....................................................    5
   3.1 Use of ifTable for DS1 Layer ...............................    5
   3.2 Usage Guidelines ...........................................    6
   3.2.1 Usage of ifStackTable for Routers and DSUs ...............    6
   3.2.2 Usage of ifStackTable for DS1/E1 on DS2/E2 ...............    8
   3.2.3 Usage of Channelization for DS3, DS1, DS0 ................    9
   3.2.4 Usage of Channelization for DS3, DS2, DS1 ................   10
   3.2.5 Usage of Loopbacks .......................................   11
   3.3 Objectives of this MIB Module ..............................   11
   3.4 DS1 Terminology ............................................   12
   3.4.1 Error Events .............................................   12
   3.4.2 Performance Defects ......................................   13
   3.4.3 Performance Parameters ...................................   14
   3.4.4 Failure States ...........................................   18
   3.4.5 Other Terms ..............................................   21
   4 Object Definitions ...........................................   22
   5.1 The DS1 Near End Group .....................................   23
   5.1.1 The DS1 Configuration Table ..............................   23
   5.1.2 The DS1 Current Table ....................................   35
   5.1.3 The DS1 Interval Table ...................................   39
   5.1.4 The DS1 Total Table ......................................   44
   5.1.5 The DS1 Channel Table ....................................   48
   5.2 The DS1 Far End Group ......................................   50
   5.2.1 The DS1 Far End Current Table ............................   50
   5.2.2 The DS1 Far End Interval Table ...........................   54
   5.2.3 The DS1 Far End Total Table ..............................   59
   5.3 The DS1 Fractional Table ...................................   63
   5.4 The DS1 Trap Group .........................................   66
   5.5 Conformance Groups .........................................   67
   5 Appendix A - Use of dsx1IfIndex and dsx1LineIndex ............   76
   6 Appendix B - The delay approach to Unavialable Seconds.  .....   79
   7 Acknowledgments ..............................................   80
   8 References ...................................................   81
   9 Security Considerations ......................................   84
   10 Author's Address ............................................   84

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