The Robust Header Compression (ROHC) Working Group was formed to develop new header compression protocols, designed to suit today's and future target link technologies. Most specifically, the ROHC protocols were to take into account typical needs presented by various wireless link technologies, and perform well for cellular links built using technologies such as WCDMA, EDGE, and CDMA-2000. Protocol development has thus focused on coping with issues such as high loss rates and long round trip times.
The WG has specified a common compression protocol platform, the ROHC framework, along with a number of compression protocols (profiles). Most focus has been on compression of the Real-time Transport Protocol (RTP) headers, but profiles have also been specified for compression of UDP, ESP, IP-only, UDP-Lite, and TCP headers. The WG has further produced a ROHC link integration specification for PPP, an optimized RTP compression scheme for "0-byte compression", a ROHC MIB, as well as various informational documents related to ROHC header compression and/or header compression in general.
In addition to the work on header compression, the ROHC WG has also developed the SigComp (Signaling Compression) protocol for end-to-end compression of text-based signaling protocol messages.
The working group maintains 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.
The current aims of the working group are:
- to carry out a re-work of the ROHC framework and profiles specifications, hereafter referred to as the ROHCv2 project. The purpose of the ROHCv2 project is to generate a separate framework specification, not changing the framework part of the ROHC protocol, as well as a set of revised compression profiles. The most specific goals with the ROHCv2 profiles are to improve tolerance to packet reordering between compressor and decompressor, and to reduce the overall complexity of the protocol. It should be noted that the v2 profiles will thus not be compatible with the original (ROHCv1) profiles, which means less complex ROHC implementations can be realized by not providing support for ROHCv1 (over links not yet supporting ROHC, or by shifting out support for ROHCv1 in the long run). Profile support is agreed through the ROHC channel negotiation, which is part of the ROHC framework and thus not changed by ROHCv2.
- to update and correct the original profile specifications through publication of the "Corrections and Clarifications to RFC 3095"- document.
- to finalize the ROHC profile work for TCP header compression.
- to develop and/or document proper protocol solutions to apply ROHC over IPsec tunnels.
- to finalize the "SigComp implementer's guide" and "SigComp for SIP" documents.
The longer term goal of the working group is to advance all its specifications to Draft Standard status (with an exception for the original profiles being revised as part of the ROHCv2 activity).
Milestones
Date
Milestone
Associated documents
Mar 2010
Conclusion of the working group.
Jun 2007
Recharter of WG to develop additional profiles if needed, or possible additional compression schemes. Consideration of concluding the working group.
Done milestones
Date
Milestone
Associated documents
Done
Revised ROHC framework submitted to IESG for publication as Proposed Standard
Done
IKE/IPsec extensions for HC-session Parameter Negotiation submitted to IESG for publication as Proposed Standard
Done
Header Compression over IPsec (HCoIPsec) submitted to IESG for publication as Informational
Done
Revised ROHC IP/UDP/RTP profiles submitted to IESG for publication as Proposed Standard
Done
SigComp Implementer's Guide submitted to IESG for publication as Proposed Standard
Done
SigComp for SIP submitted to IESG for publication as Proposed Standard
Done
ROHC framework submitted to IESG for publication as Proposed Standard
Done
IP/TCP compression scheme submitted to IESG for publication as Proposed Standard
Done
RFC 3095 Implementer's Guide submitted to IESG for publication as Proposed Standard
Done
I-Ds of ROHC IP/UDP/RTP bis, framework and profiles separated.
Done
Problem analysis ROHC-over-channels-that-can-reorder-packets submitted to IESG for publication as Informational
Done
Requirements for IP/TCP header compression submitted to IESG for publication as Informational.
Done
ROHC UDP Lite schemes submitted to IESG for publication as Proposed Standard.
Done
ROHC IP-only profile submitted to IESG for publication as Proposed Standard
Done
ROHC MIB submitted to IESG for publication as Proposed Standard.
Done
General signaling compression security analysis submitted to IESG for publication as Informational.
Done
Layer-2 design guidelines submitted to IESG for publication as Informational.
Done
Initial draft on general signaling compression security analysis.
Done
Signaling compression scheme submitted to IESG for publication as Proposed Standard, including security approach for SIP compression usage.
Done
Requirements and assumptions for signaling compression
Done
IP/UDP/RTP header compression scheme submitted to IESG for publication as Proposed Standard.
Done
Submit I-D on IP/TCP header compression scheme.
Done
Resolve possibly multiple IP/UDP/RTP compression schemes into a single scheme.
Done
Requirements for IP/UDP/RTP header compression submitted to IESG for publication as Informational.