Lossless data compression has commonly been deployed in layers below IP (PPP being one example). However, the anticipated deployment of higher-layer encryption protocols (e.g., IPSec) threatens to reduce the effectiveness of lower-layer compression techniques since encrypted data cannot be compressed. The IP Payload Compression Protocol Working Group will develop protocol specifications that make it possible to perform lossless compression on individual payloads before the payload is processed by a protocol that encrypts it. These specifications will allow for compression operations to be performed prior to the encryption of a payload by such protocols as IPSec. The Working Group will focus on the compression of independent payloads (i.e., independent datagrams) in a stateless manner. By stateless, we mean that decompression of a received packet does not rely on correct reception or correct ordering of previous packets. The immediate problem the Working Group will address is the development of a payload compression protocol for use in conjunction with IPSec. The working group will develop its specifications to support both IPv4 and IPv6. Although the primary motivation for this WG is the need to compress packets when IPSec is used, the WG will develop an architecture that does not preclude its use with other potential protocols or the absence of IPSec. The working group will identify and document the mechanisms that allow two communicating parties to negotiate the use of compression as well as the compression format to be employed. The Working Group will consider defining extensions to ISAKMP to support the negotiation of compression parameters. Use of ISAKMP as the immediate effort shall not preclude compression in the absence of IPsec. Alternate negotiation mechanisms (or even static negotiation), if appropriate, shall be identified and extended as needed to accommodate the use of payload compression functionality. Since compression will be negotiated, existing implementations of IP will interoperate with implementations that support compression. The output of this WG will consist of a base architectural document that provides the framework for how compression will be done (i.e., defines the compression "shim"), together with one or more documents giving specific compression algorithms and formats. The architectural document will describe how different compression algorithms can be negotiated and supported, but the documenting of specific compression algorithms will be done elsewhere (i.e., in standalone documents). A registration mechanism for various compression formats will be specified as part of the base protocol. If possible, an existing registration mechanism for compression formats shall be used (e.g., Compression Control Protocol options of PPP).