Subject: [AVT] Proposal for update of AVT charter and milestones

From: Magnus Westerlund <[email-masked]>
Date: Tue, 18 Jan 2005 09:40:09 +0100

Hi,

AVT is in need for an updated charter and milestones. Below is the 
proposal for these items. Please comment on these before Wednesday 26th 
of January.

Cheers

Magnus

--- Charter proposal begins -----

The Audio/Video Transport Working Group was formed to specify a
protocol for real-time transmission of audio and video over unicast
and multicast UDP/IP. This is the Real-time Transport Protocol, RTP,
together with its associated profiles and payload formats. The
current aims of the working group are:

- to review and revise existing payload formats to advance those
   which are useful to Draft Standard, and to declare others
   as Historic. Milestones will be established as a champion for
   each payload format is identified.

- to develop payload formats for new media codecs, and to
   document best-current practices in payload format design.
   The group continues to be precluded from work on codecs
   themselves because of overlap with the other standards
   bodies, and because the IETF does not have the ability
   to effectively review new codecs. An exception was made
   for the freeware iLBC codec on a highly experimental basis,
   but acceptance of new codec work is unexpected and subject
   to rechartering.

- to complete the forward error correction work to update
   RFC 2733 in the form of the ULP payload format

- to investigate and if suitable develop a framework for advanced
   FEC codes and their usage for RTP, possibly with alignment to
   the RMT WG's FEC building block.

- to extend RTP to work with Source-Specific Multicast sessions
   with unicast feedback

- to provide a framing mechanism for RTP over TCP and TLS

- to in collaboration with the MPLS and ROHC WG develop a solution
   for header compression of RTP across MPLS networks that avoid
   decompression and compression at each MPLS node.

- to develop a new RTP profile as the combination of the SRTP
   profile and the Extended RTP Profile for RTCP-based Feedback
   (RTP/SAVPF)

- to develop an new experimental RTP profile for usage of TFRC
   (RFC 3448) with RTP over UDP to allow application developers
   to gain experience with TCP friendly congestion control.

- to develop an MIB for RTCP XR (RFC 3611).

The longer term goals of the working group are to advance the
SRTP Profile, the Extended RTP Profile for RTCP-based Feedback,
the Compressed RTP framework, and the RTP MIB to Draft Standard.

The group has no plans to develop new RTP profiles beyond those
listed above, but will consider rechartering to produce profile
level extensions if appropriate.

Goals and Milestones:

May 05	  	Submit RTP/SAVPF profile for Proposed Standard
May 05	  	Submit RTCP/SSM draft for Proposed Standard
Nov 05	  	Submit ULP Payload Format for Proposed Standard
Nov 05	  	Submit Framing of RTP for TLS for Proposed Standard
Nov 05	  	Submit update of RTP MIB for Draft Standard
Nov 05 		Submit RTP Profile for TFRC for Experimental Status
Nov 05	  	Finished investigation of advanced FEC codes for RTP, update plan
Dec 05		Submit any extensions for RTP HC on MPLS networks for Proposed 
Standard
Mar 06	  	Submit SRTP for Draft Standard
Sep 06	  	Submit RTP/AVPF for Draft Standard

----- Charter proposal ends ----

Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVA/A
----------------------------------------------------------------------
Ericsson AB                | Phone +46 8 4048287
Torshamsgatan 23           | Fax   +46 8 7575550
S-164 80 Stockholm, Sweden | mailto: [email-masked]

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

---

From: Ladan Gharai <[email-masked]>
Date: Wed, 19 Jan 2005 14:40:46 -0500

Magnus:

I have a question regarding the charter update and the RTP profile for 
TFRC.

The RTP profile for TFRC defines  modifications need to RTP/RTCP to 
support TFRC. These modifications are pretty generic: RR extensions and 
new fields to the RTP header.

The  RTP/RTCP protocol is a mature standard with a number of other 
profiles (all standards track) and the TFRC mechanism itself, is a 
proposed standard.

What is the rational of advancing the RTP profile for TFRC as an 
experimental as opposed to proposed standard?

Ladan

---

From: Magnus Westerlund <[email-masked]>
Date: Fri, 28 Jan 2005 13:51:32 +0100

Hi Ladan and the WG,

The proposal for experimental status is based on the discussion and 
development that has happened in this area.

- Although RTP is a mature protocol. The usage of TFRC with RTP is 
clearly not a mature subject. The discussion, mostly in the DCCP WG, 
around this topic clearly shows that. There is a lot of different ideas 
and opinions but not that much real experience.

- This work has been presented as a way to gain more experience for RTP 
application developers with TFRC. Without the experience I at least are 
uncertain that we are defining a profile that will have the necessary 
features.

- We also have the rather major issue what happens with TFRC when the 
RTT is low and the TFRC feedback requires more bandwidth than what is 
available. That we can find a solution that is suitable for general 
deployment without substantial experiments is not that likely.

Thus experimental status seems the appropriate step until we have gained 
  experience with TFRC for RTP. If we manage to get everything right the 
first time then it is easy to move the specification from experimental 
to standards track.

Cheers

Magnus

-- 

Magnus Westerlund