Minutes IETF101: mmusic

Meeting Minutes Multiparty Multimedia Session Control (mmusic) WG
Title Minutes IETF101: mmusic
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Last updated 2018-04-06

Meeting Minutes

   MMUSIC Working Group at IETF 101
The MMUSIC working group met at IETF #101 in London, UK on Friday, March 23,
2018 from 9:30 to 10:30. The meeting was chaired by Flemming Andreasen and Bo
Burman. Roni Even and the chairs took notes, and Jonathan Lennox acted as
Jabber relay. The meeting was broadcast live and recorded by the Meetecho team.
The recording is available at:

Below is the final agenda:
9:30-9:45       Introduction and Status Update (15 mins, Chairs)
9:45-10:00      4566bis (15 mins, Ali Begen)
10:00-10:30     SDP Offer/Answer Procedures for ICE – Open Issues (30 mins,
Suhas Nandakumar)

Introduction and Status Update

The chairs presented their slides with the agenda and an update about the
activities since the last meeting. The chairs were looking for feedback on
draft-ietf-mmusic-sdp-uks. Jonathan Lennox and Marc Petit-Huguenin offered to


Ali Begen presented the slides () summarizing the open issues, numbered as
discussed on the mailing list:
    *   Open Issue #3 - What is the time zone for the start and stop
        sub-fields, and what is the relation to the time zone adjustment field?
        It is UTC and time zone adjustment is to handle daylight saving for
        repeated meetings.
    *   Open Issue #4 - Are values integers or real (as decided at IETF 92),
        and what of Magnus’ recommendation to only use with fmtp and deprecate
        on media stream level?
        Flemming and Colin objected to deprecate on media stream level. There
        was support in the room to allow usage of fractional values and it
        will therefore be kept.
    *   Open Issue #7 - Why is existing registration of RTP/SAVP in RFC 3711
        not used and what should we do with current udptl registration that
        references T.38 but should rather reference RFC 7345?
        There was some discussion on RTP/SAVP, concluding that 4566bis should
        only register what RFC 4566 did, RTP/AVP and UDP, remove mentioning
        SAVP and just say that there are other “proto” registrations.
        There was also discussion on how to handle udptl, concluding that the
        registry information for udptl is incorrect but that 4566bis will
        grandfather T.38 and keep the text as is. The currently defined
        registration procedure should however be changed to not only allow
        referencing standards track RFC. [Action: Authors]
    *   Open Issue #8 - Where are media format (“fmt”) registrations to be
        Colin commented that the only “proto” that currently has a
        well-defined registration policy (in RFC 3555) are the ones based on
        RTP. A discussion concluded to clarify that the media format namespace
        and registration procedures depends on “proto” value and that “fmt”
        registration procedures must also be specified when registering a new
        “proto”. Jonathan offered to provide text giving some guidance.
        [Action: Jonathan and authors]
    *   Open Issue #9 - Should IANA registration of “CT” and “AS” bandwidth
        specifiers be updated to point to 4566bis instead of to RFC 4566 and
        draft-ietf-mmusic-sdp-mux-attributes as today?
        Ben C commented that the current text “should be registered” seems
        un-enforceable and that the WG should pick a text pointing to one of
        the currently defined procedures. This is also applicable to open
        issue #7. It was concluded to re-check IANA registry and refine text
        in 4566bis accordingly. [Action: Authors]

SDP Offer/Answer Procedures for ICE - Open Issues

Marc Petit-Huguenin presented the slides (). The authors and Christer H had met
during the IETF week to discuss the remaining issues. Marc said that there
should soon be responses to comments on the mailing list and that a new version
could be expected before May. Ben C expressed concern about the long time.
Chairs will contact authors and try to expedite draft progress [Action: chairs].