CLUE Signaling (draft-kyzivat-clue-signaling-05) Sept 17, 2012 Editor: Paul Kyzivat

Major Open Issues (repeated from IETF87) Relationship between CLUE messages & SDP Representation of encodings: SDP or ADV Approach to message responses (ack/nak/error) Elaboration of message sequencing Legacy mode CLUE channel Message Syntax Details Approach to versioning/options/extensions Approach to message encoding: stand-alone or deltas Examples/call flows  The document is a mess – poor organization and inconsistent Sept 17, 2013draft-kyzivat-clue-signaling-052

Who will do this work? Five or six people expressed interest: – Roni Even, Rob Hansen, Christer Holmberg, Paul Kyzivat, Roberta Presta, Simon Romano, (?)Jonathan Lennox We need a few to do a huge amount of work, or all to do substantial work. It isn’t going to happen without specific commitments – To make proposals – Lead design team discussion of subject – Provide text for signaling document Looking for commitments today! Sept 17, 2013draft-kyzivat-clue-signaling-053

Relationship between CLUE messages & SDP No changes since Berlin – suggest we revisit after progress in other areas Sept 17, 2013draft-kyzivat-clue-signaling-054

Representation of Encodings: SDP or ADV Rob has proposed putting encoding representation in SDP, not in the ADV Current signaling draft assumes this approach – Just a trial, subject to change Needs careful evaluation: – It seems to require a lot of O/As – Moving encodings to ADV might save O/As – Maybe we need to try both ways and compare Need a volunteer to do this – else don’t complain later that this was a bad choice Sept 17, 2013draft-kyzivat-clue-signaling-055

Approach to message responses (ack/nak/error) Signaling draft -05 has a response for every request Needed when more requests added I think presta-protocol could easily work with this Can we agree to go forward with this? I (Paul) am willing to own this Sept 17, 2013draft-kyzivat-clue-signaling-056

Elaboration of message sequencing This needs to be worked out at multiple levels – Sequencing of CLUE messages State machine for version negotiation State machine for provider State machine for consumer Coupling between peer provider & consumer Coupling between collocated provider & consumer – Sequencing/dependency between CLUE messages and SDP offers/answers – Transition between CLUE and legacy modes – Relation to CLUE channel lifetime presta-clue-protocol is a start I’m assuming Roberta owns this for the sequencing of provider & consumer messages I (Paul) volunteer to own the version negotiation Need volunteers for the rest Sept 17, 2013draft-kyzivat-clue-signaling-057

Legacy Mode Christer volunteered to own this Waiting for a proposal Sept 17, 2013draft-kyzivat-clue-signaling-058

CLUE channel Current proposal is to use: – SCTP over DTLS over UDP – draft-ietf-mmusic-sctp-sdp-nn for setup – Single SCTP stream in each direction (equivalent to an RTCWEB Data Channel) – Single SCTP message per CLUE message – No additional message framing other than what is included in message syntax Assuming this is settled Small work to put details into draft. Sept 17, 2013draft-kyzivat-clue-signaling-059

CLUE channel lifetime & error handling (Re)Establishment of SCTP association signaled by SDP per RFC 4145 (comedia) – O/A to request a new association What state is tied to CLUE channel? How does CLUE channel state relate to SCTP association state? What happens when an error is detected on CLUE channel of SCTP association? – Do most recent ADV & CFG remain in effect? – Attempt to reestablish SCTP? May CLUE channel be intentionally dropped if further use is not expected? – Should other side then attempt to reestablish if it wants to send ADV or CFG? – How to prevent continued attempts at reestablishment? Need specific text about this in the signaling draft. I think Christer volunteered to own this. Sept 17, 2013draft-kyzivat-clue-signaling-0510

Message Syntax Details XML is agreed Basic message syntax defined in signaling draft – Significant content by reference to data model syntax Current details are just a straw horse – Only Roberta has commented on it I (Paul) will own this if need be, but a more XML literate volunteer might be better. Sept 17, 2013draft-kyzivat-clue-signaling-0511

Approach to versioning/options/extensions Proposal floated in design team last week. Based on that, added a proposal to the signaling draft Needs polishing Biggest issues remaining: – Precise definition of backward compatibility – Rules for assigning version numbers I (Paul) volunteer to own this Sept 17, 2013draft-kyzivat-clue-signaling-0512

Approach to ADV/CFG encoding stand-alone or deltas Agreed to proceed with stand-alone – Add deltas later if they are needed. Propose we don’t discuss any more Sept 17, 2013draft-kyzivat-clue-signaling-0513

Examples & call flows Do we have any volunteers who like to do these? If not, I suggest work on other parts do what they need, and we postpone other work on this till later. Sept 17, 2013draft-kyzivat-clue-signaling-0514

The document is a mess ( poor organization and inconsistent) It needs some careful editing I (Paul) have been doing this, but I’m not great at it. Does anybody want to volunteer for this? Sept 17, 2013draft-kyzivat-clue-signaling-0515

Volunteers Roni Even Rob Hansen Christer Holmberg Legacy, clue channel lifetime Paul Kyzivat ACK/NAK, msg syntax, versioning, draft editing Roberta Presta Producer/consumer msg sequencing Simon Romano (?)Jonathan Lennox Sept 17, 2013draft-kyzivat-clue-signaling-0516

Task Ownership Task/IssueOwnerNext StepWhen Eval of Encoding in SDP?Define alternative. Do comparison.? Mech. For msg responsesPaulDiscuss at design team meeting.Ready now. Message Sequencing - VersioningPaulRespond to feedback to draft changes. - Producer/ConsumerRobertaMake new version based on feedback. Discuss at design team meeting. - CLUE vs. SDP?Provide text and call flows for sig draft? - CLUE channel lifetimeChristerPropose, then discuss at design team? - CLUE vs. legacy modeChristerProvide text and call flows for sig draft Legacy ModeChristerPropose behavior on list, then discuss at design team CLUE channel mechanism?Propose text for details. Review on list. Msg syntax detailsPaul?Revise/improve/maintain schema Versioning & OptionsPaulRevise draft based on feedbackas needed Message Deltas(none – done) Call flows & Examples?Propose text. Review on list. Document Org & editingPaul? Sept 17, 2013draft-kyzivat-clue-signaling-0517