Protocol Action: Signaling Compression to Proposed Standard

[The IESG <iesg-secretary@ietf.org>]

The IESG has approved the Internet-Draft 'Signaling Compression'
<draft-ietf-rohc-sigcomp-07.txt> as a Proposed Standard.

In the same action, the following Internet-Drafts were approved for
publication as Informational RFCs:

o SigComp - Extended Operations
	<draft-ietf-rohc-sigcomp-extended-04.txt>
o Signaling Compression Requirements & Assumptions
	<draft-ietf-rohc-signaling-req-assump-06.txt>



These documents are the product of the Robust Header Compression
Working Group.  The IESG contact persons are Allison Mankin and Scott
Bradner.

 
Technical Summary
 
      Many application protocols used for multimedia communications are
      text-based and have not been optimized in terms of size. For
      example, typical SIP messages range from a few hundred bytes up
      to two thousand bytes or more.

      With the planned usage of these protocols in wireless handsets as
      part of 2.5G and 3G cellular networks, the large message size is
      problematic, especially because of transmisssion delay concerns.
      Taking into account retransmissions, and the multiplicity
      of messages that are required in some flows, call setup
      and feature invocation are adversely affected. SigComp provides a
      means to eliminate this problem by offering robust, lossless
      compression of application messages.

      The Sigcomp document presents the architecture and pre-requisites of the
      SigComp solution, the format of the SigComp message and the Universal
      Decompressor Virtual Machine (UDVM) that provides decompression
      functionality. Arbitary applications ar supported by transferring
      a well-formed UDVM for the use of a flow or flows from the sender
      to the receiver.

      SigComp is offered to applications as a layer between the application
      and an underlying transport. The service provides is that of the
      underlying transport plus compression. SigComp supports a wide range
      of transports including TCP, UDP and SCTP [RFC-2960].

      The two informational drafts provide background to the design
      (requirements) and a set of optimization techniques for UDVM
      construction (extended operations) that may either be adopted by
      implementations or used as a model for optimizations to be
      added in future.
 
Working Group Summary
 
  The working group had strong agreement to advance these drafts.
 
Protocol Quality

    No problems were found during IETF Last Call. There have been
    two independent prototyping developments of sigcomp, with
    resuls of both the protocol and interoperation tests being
    fed into the working group effort before last call. Allison
    Mankin reviewed the documents for the IESG.