FECFrame Minutes, IETF 68, Prague Mark presenting FECframe document update: - requirement status is frozen, no comments since ietf67 - open issues: - Fec scheme requirements - Most requirements can be likely imported from RMT - Lorenzo: feedback from RMT: good to have this scheme definition to have good quality of resulting FEC drafts later on - Q: are there any transport specific considerations - considered: UDP and DCCP - Rajiv Asati: L4 ? Yes. - Q: has RTP been cnsidered ? Currently arbitrary flow across UDP - includes of course RTP (on top of RTP). A: nothing specific to RTP currently. RTP is on top of UDP. Other groups (DVB) have tried to do this. Pro and Cons of trying to be specific to RTP. - James Wendel/Microsoft: RTP is also a framework in itself. there are fields in RTP obvious you wold want to exploit. RTP is for time critical flows. Some impact on semantics too. - Greg/Mark: Specific FEC scheme could rely on existing RTP fields and not need to add them to it's own header. ALso backward compatible - Lorenzo: Hybrid scheme possible ? (Header format that is flexible to be optimized with RTP as payload vs. non RTP payload). Mark: Mostly documentation issue. - CMagnus: (didn't understand what he said) - Lorenzo: Add permanent piece of header and optional header only present when payload is not RTP. - Magnus: probably not useful from complexity perspective. - sdp elements... description of properties of toolkit of SDP elements to be used in content delivery protocols. Not normative, but indicidual FEC schemes may choose to use them. - transport protocol identifiers for FEC repair flows - Association of source flows to repair flow - FEC-scheme specific configuration - Greg: Rosetta stone draft needed describing where information is being pulled in from (RMT specs, etc..) - Rajiv: Why SDP ? Mark: Not manadated, optional. - SPD requires coordination with mmusic, avt and rmt. Next Steps: - Streaming Content Delivery Protocol. Need to defne a specific protocol, maybe based on SDP toolkit, provide explicit example cases. Have an example of a concrete example of how to use the framework. - Greg/Mark: separate document from Framework. - (Unnamed) Proposal: Just use XOR as a simple example - Lorenzo: What plans to take from what RMT did ? - Mark: Could be lot of reuse of RMT work. Maybe just a few pages spec in FEC frame and refer to an algorithm defined in RMT. - Mark: Do we want to systematically pull in RMT ? Probably not, leave it up to proponents of individual schemes. - Lorenzo: IANA registration defined ? - Mark: not yet. Probably in future. Three choices: - Dfine when signaling of FEC is defined - Do same thing as RMT did (signaling independent code space) - Directly clone/reuse RMT defined code space. - Rajiv: Preferred solution to reuse work from RMT - Magnus: Only 256 code points in RMT definition. Maybe too little. Especially with dynamic mapping.