Subject: Protocol Action: 'RTP-mixer formatting of multiparty Real-time text' to Proposed Standard (draft-ietf-avtcore-multi-party-rtt-mix-20.txt)

From: The IESG <[email-masked]>
Date: Wed, 26 May 2021 08:25:10 -0700

The IESG has approved the following document:
- 'RTP-mixer formatting of multiparty Real-time text'
  (draft-ietf-avtcore-multi-party-rtt-mix-20.txt) as Proposed Standard

This document is the product of the Audio/Video Transport Core Maintenance
Working Group.

The IESG contact persons are Murray Kucherawy and Francesca Palombini.

A URL of this Internet Draft is:
https://datatracker.ietf.org/doc/draft-ietf-avtcore-multi-party-rtt-mix/

Technical Summary:

   Enhancements for RFC 4103 real-time text mixing are provided in this
   document, suitable for a centralized conference model that enables
   source identification and rapidly interleaved transmission of text
   from different sources.  The intended use is for real-time text
   mixers and participant endpoints capable of providing an efficient
   presentation or other treatment of a multi-party real-time text
   session.  The specified mechanism builds on the standard use of the
   CSRC list in the RTP packet for source identification.  The method
   makes use of the same "text/t140" and "text/red" formats as for two-
   party sessions.

   Solutions using multiple RTP streams in the same RTP session are
   briefly mentioned, as they could have some benefits over the RTP-
   mixer model.  The possibility to implement the solution in a wide
   range of existing RTP implementations made the RTP-mixer model be
   selected to be fully specified in this document.

   A capability exchange is specified so that it can be verified that a
   mixer and a participant can handle the multi-party coded real-time
   text stream using the RTP-mixer method.  The capability is indicated
   by use of an SDP media attribute "rtt-mixer".

   The document updates RFC 4103 "RTP Payload for Text Conversation".

   A specification of how a mixer can format text for the case when the
   endpoint is not multi-party aware is also provided.

Working Group Summary:

WG Last Call of "RTP-mixer formatting of multi-party Real-time text" was
announced on November 25, 2020:
https://mailarchive.ietf.org/arch/msg/avt/tjGlWlXL5a54nhgl5nRV3jkD_tk/

WGLC concluded on December 9, 2020.

Of the 6 participants responding to the WGLC, 3 supported Advancement to
Proposed Standard, and 3 respondents provided comments, which were addressed
by the author. 

Document Quality:
There are no existing implementations of the specification.  

Personnel:

Document Shepherd is Bernard Aboba. Responsible AD is Murray Kucherawy.