Subject: [AVTCORE] AVTcore IETF86 minutes

From: "Roni Even" <[email-masked]>
Date: Tue, 2 Apr 2013 12:28:44 +0300

Hi,

Here are the minutes of the AVTcore session. Please review 

Magnus and Roni

Audio/Video Transport Core Maintenance  (AVTCore) Working Group meeting
notes

===============================================================

CHAIRS:  Magnus Westerlund       [email-masked]

                Roni Even         [email-masked]

Notes taker: Paul Kyzivat

Jabber Scribe: Jonathan Lennox

Tuesday, 12 March 2013 

AVTCore Status Update - chairs                  

The slides are in
http://www.ietf.org/proceedings/86/slides/slides-86-avtcore-0.pdf.

Draft-ietf-avt-srtp-not-mandatory-12 is still in IESG processing it is
waiting for progress of draft-ietf-avtcore-rtp-security-options-02 which
reviews the different RTP security options, the security options draft need
reviews by security experts as well as others since it gives guidance for
developers on how to choose the appropriate security mechanism.

draft-ietf-avtcore-aria-srtp-01 is ready for WGLC but need more SRTP
security expert review.

The authors of draft-ietf-avtcore-srtp-aes-gcm-05 added a section on RTP
header extension encryption and the document needs a second WGLC before
going to publication.

We are waiting for an update of draft-ietf-avtcore-srtp-ekt-00 and we can
probably start a WGLC when it is submitted.

draft-ietf-avtcore-6222bis-00 need an update and will be ready for WGLC.
Update was submitted during the meeting and WGLC started after the meeting.

draft-ietf-avtcore-avp-codecs-00 need an update and will be ready for WGLC.
Update was submitted during the meeting and WGLC started after the meeting.

draft-ietf-avtcore-multi-media-rtp-session-02 had some open issues mostly on
multi-streams and not on multi media types. The view in the meeting after
discussing draft-lennox-avtcore-rtp-multi-stream-02 is that multi-streams
topic will be part of the Lennox draft so a revision of
multi-media-rtp-session is needed.

draft-ietf-avtcore-idms-09 will go to publication. Publication request was
sent after the meeting.

draft-westerlund-avtcore-multiplex-architecture-03 is an informational
document. There was support in the meeting to have it as a WG document. Will
verify on the list 

There was support to have draft-westerlund-avtcore-rtp-topologies-update-02
as a WG document and it will be verified on the list.

RTP Considerations for Endpoints sending multiple media streams in
draft-lennox-avtcore-rtp-multi-stream-02 was presented by Jonathan Lennox. 

The slides are in
http://www.ietf.org/proceedings/86/slides/slides-86-avtcore-4.pdf. 

The draft addresses the issue with supporting multiple sources in an RTP
session since current solution will usually support only one source per RTP
session. The draft re-visits RFC 3550 to clarify behavior for multi-source
endpoints and suggests that there may be a need to update RFC 3550 to change
some RTCP timing rules.  It proposes recommendations on optimizations for
reception reports. 

This revision incorporates
draft-wu-avtcore-multiplex-multisource-endpoint-01 and has new solution
based on meeting between the authors of both drafts at IETF85.

There were no issues with the author's proposals for how deal with the open
issues. 

On the way forward there was some discussion about the content of this draft
and draft-ietf-avtcore-multi-media-rtp-session-02. There was support to have
this document as a WG document and it will be verified on the list.

It seems like the draft will include clarifications of rtcp size and timing
that are now in draft-ietf-avtcore-multi-media-rtp-session-02.

RTP Congestion Control: Circuit Breakers for Unicast Sessions in
draft-ietf-avtcore-rtp-circuit-breakers-02 presented by Colin Perkins.

The slides are in
http://www.ietf.org/proceedings/86/slides/slides-86-avtcore-1.pdf  

RTP circuit breakers provide an envelope within which congestion control can
operate. Circuit breakers are conditions under which an RTP sender needs to
stop transmitting media data to protect the network from excessive
congestion. Colin presented the changes in this revision

There was a comment from Jonathan Lennox that the draft need to take into
account the reporting groups if they will be accepted as a solution and not
only reduced size RTCP.

Colin says he has no open issues.

There are some experimental implementations that will be presented at the
next meeting. There was a request for help with implementation experience.

RTP Clock Source Signalling presented by Kevin Gross

The slides are in
http://www.ietf.org/proceedings/86/slides/slides-86-avtcore-2.pdf.

The draft proposes a solution to explicitly signal clock information in RTP
including timestamp reference clock and media clock. 

Magnus Westerlund and Bo Burman volunteered to review the O/A portion of the
document. The document is ready for WGLC.

RTP and Leap Second presented by Kevin Gross

The slides are in
http://www.ietf.org/proceedings/86/slides/slides-86-avtcore-3.pdf.

This document discusses issues that arise when RTP sessions span Universal
Coordinate Time (UTC) leap seconds.  It updates RFC 3550 to describe how RTP
senders and receivers should behave in the presence of leap seconds.

Colin Perkins wondered if sending sender report would be better than
reception report. Kevin Gross thought that might confuse some devices. Colin
replied "maybe". Jonathan Lennox said even if you don't send anything during
the event, could you still have a problem. Conclusion that this is a problem
only if the two sides disagree whether there is a leap second.

The draft is ready for WGLC but it will be after the clock source signaling
draft.