[RTW] Charter proposal: The activity hitherto known as "RTC-WEB at IETF"

[Harald Alvestrand]

This is the first of 3 messages going to the DISPATCH list (in the hope 
of keeping discussions somewhat organized).

This is the draft of a charter for an IETF working group to consider the 
subject area of "Real time communication in the Web browser platform". 
This is one of a paired set of activities, the other one being a W3C 
activity (either within an existing WG or in a new WG) that defines APIs 
to this functionality.

The two other messages will contain the W3C proposed charter and a 
kickoff for what's usually the most distracting topic in any such 
discussion: The name of the group.
Without further ado:

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Version: 2

Possible Names:
<This space deliberately left blank for later discussion>

Body:

Many implementations have been made that use a Web browser to support 
interactive communications directly between users including voice, 
video, collaboration and gaming, but until now, such applications have 
required the installation of nonstandard plugins and browser extensions. 
There is a desire to standardize such functionality, so that this type 
of application can be run in any compatible browser.

Traditionally, the W3C has defined API and markup languages such as HTML 
that work in conjunction with with the IETF over the wire protocols such 
as HTTP to allow web browsers to display media that does not have real 
time interactive constraints with another human.

The W3C and IETF plan to collaborate together in their traditional way 
to meet the evolving needs of browsers. Specifically the IETF will 
provide a set of on the wire protocols, including RTP, to meet the needs 
on interactive communications, and the W3C will define the API and 
markup to allow web application developers to control the on the wire 
protocols. This will allow application developers  to write applications 
that run in a browser and facilitate interactive communications between 
users for voice and video communications, collaboration, and gaming.

This working group will select and define a minimal set of protocols 
that will enable browsers to:

* have interactive real time voice and video between users using RTP
* interoperate with compatible voice and video systems that are not web 
based
* support direct flows of non RTP application data between browsers for 
collaboration and gaming applications

Fortunately very little development of new protocol at IETF is required 
for this, only selection of existing protocols and selection of minimum 
capabilities to ensure interoperability. The following protocols are 
candidates for including in the profile set:

1) RTP/ RTCP

2) a baseline audio codec for high quality interactive audio. Opus
will be considered as one of the candidates

3) a baseline audio codec for PSTN interoperability. G.711 and iLBC
will be considered

4) a baseline video codec. H.264 and VP8 will be considered

5) Diffserv based QoS

6) NAT traversal using ICE

7) RFC 4833 based DTMF transport

8) RFC 4574 based Label support for identifying streams purpose

9) Secure RTP and keying

10) support for IPv4, IPv6 and dual stack browsers

The working group will cooperate closely with the W3C activity that 
specifies a semantic level API that allows the control and manipulation 
of all the functionality above. In addition, the API needs to 
communicate state information and events about what is happening in the 
browser that to applications running in the browser. These events and 
state need to include information such as: receiving RFC 4833 DTMF, RTP 
and RTCP statistics, state of DTLS/SRTP,  and signalling state.

The following topics will be out of scope for the initial phase of the 
WG but could be added after a recharter: RTSP, RSVP, NSIS, LOST, 
Geolocation, IM & Presence, NSIS, Resource Priority,

Milestones:

February 2011 Candidate "sample" documents circulated to DISPATCH

March 2011 BOF at IETF Prague

April 2011 WG charter approved by IESG. Chosen document sets adopted as 
WG documents

May 2011 Functionality to include and main alternative protocols identified

July 2011 IETF meeting

Aug 2011 Draft with text reflecting agreement of what the protocol set 
should be

Nov 2010 Documentation specifying mapping of protocol functionality to 
W3C-specified API produced

Dec 2011 Protocol set specification to IESG

April 2012 API mapping document to IESG