Subject: DS1 Channelization

From: "Laurence V. Marks" <[email-masked]>
Date: Thu, 5 Feb 98 15:15:26 EST

Ref:  Your note of Thu, 5 Feb 1998 11:54:38 -0800 (PST) (attached)

>
> From the questions I have recently asked around here, I believe you
> are absolutely correct.  In fact, I understand that it would be an
> oddity to actually see a DS2 interface presented electrically, and
> that it tends only to exist within the M13 mux chips that you refer to.
>
They exist (or at least were planned to exist, I think), in telco
offices for cross-connect purposes.  E.g., On an NY-to-LA DS-3, they
could split off four DS-1s destined for St. Louis as a DS-2.

> It kind of makes me wonder about several things then:
>
> - Why did we select (in RFC 1407) the terminology of "dsx3M23(2)"
>   for the dsx3LineType instead of "dsx3M13(2)".  I can't tell you
>   the number of times people have asked about why no M13 option
>   was presented, and I have always responded by saying that the
>   two are really the same and the DS3-MIB creators simply chose
>   the term they did.  (At the same time while responding this way,
>   I have always internally wondered why this choice was made that
>   way, nevertheless.)
>
Don't know.  I haven't followed the DS-3 much.  At the time I got
involved I was working on an ISDN PRI (DS-1) unit, but both share the
same mailing list.

> - Where is the interest in supporting DS2 interfaces coming from?
>
>   I can see the value in having J2 supported by these MIBs (although
>   it is not, currently), since it is actually in use in Japan.  (I
>   would be happy to propose any necessary ASN.1 modifications to add
>   J2 support if there is one or more other vendors interested in it.)
>
>   But who actually presents DS2 interfaces in the physical sense?  If
>   they exist only logically, but are always bypassed in the DS3 to DS1
>   channelization process, then why are they needed?  Does anybody know
>   who originally requested that support for DS2 (and E2 for that matter)
>   be added to the DS1-MIB?
>
Possibly the telcos themselves are interested, (supposing they do
cross-connect DS-2s).  Do you know if telcos use SNMP for management?

>   The same question goes for E2, especially since I am unfamiliar with
>   the frequency of its use around the world.
>
> Gary
To the best of my knowledge, some European carriers do offer E2 access
to customers.
Laurence V. Marks