Robust Header Compression WG (rohc)

Friday, March 31 at 0900-1130
=============================

CHAIRS: Mikael Degermark <micke@optima.CS.Arizona.EDU>  
        Carsten Bormann <cabo@tzi.org>

DESCRIPTION:

Due to limited bandwidth, IP/UDP/RTP/TCP packets sent over cellular 
links benefit considerably from header compression.  Existing header 
compression schemes (RFC 1144, RFC 2508) do not perform well over 
cellular links due to high error rates and long link roundtrip times, 
particularly as topologies and traffic patterns become more complex.  In 
addition, existing schemes do not compress TCP options such as SACK or 
Timestamps.

The goal of ROHC is to develop header compression schemes that perform
well over links with high error rates and long roundtrip times. The 
schemes must perform well for cellular links built using technologies 
such as WCDMA, EDGE, and CDMA-2000. However, the schemes should also be 
applicable to other future link technologies with high loss and long 
roundtrip times. Ideally, it should be possible to compress over 
unidirectional links.

Good performance includes both minimal loss propagation and minimal 
added delay.  In addition to generic TCP and UDP/RTP compression, 
applications of particular interest are voice and low-bandwidth video.

ROHC may develop multiple compression schemes, for example, some that
are particularly suited to specific link layer technologies.  Schemes
in addition to those listed in the milestones below may be added in
consultation with the area directors.

A robust header compression scheme must:

* assure that when a header is compressed and then decompressed, the
  result is semantically identical to the original;

* perform well when the end-to-end path involves more than one
  cellular link;

* support IPv4 and IPv6.

Creating more thorough requirements documents will be the first task
of the WG.

The working group shall maintain connections with other standardization
organizations developing cellular technology for IP, such as 3GPP and
3GPP-2, to ensure that its output fulfills their requirements and will 
be put to good use.

In addition, the WG should develop a solid understanding of the
impact that specific error patterns have on the compression schemes,
and document guidelines to Layer 2 designers regarding what Layer 2
features work best to assist Layer 3 and Layer 4 header compression.

Finally, working group documents will address interactions with IPSEC 
and other security implications.

AGENDA:

Presentation of WG charter & WG staff
         Degermark/Bormann

Agenda bashing

Header compression requirements draft
         Degermark

Layer-2 guidelines draft
         Svanbro

ROCCO
         Jonsson

ACE
         ??, Nokia


ROCCO profile for low-bandwidth Video
         Jonsson

Robust header compression for TCP 
         Nordgren
         
Header compression in (encrypted) tunnels
         Degermark