Robust Header Compression WG (rohc) Friday, March 31 at 0900-1130 ============================= CHAIRS: Mikael Degermark Carsten Bormann 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