Re: [MMUSIC] I-D Action: draft-ietf-mmusic-sctp-sdp-02.txt

[Harald Alvestrand <[e-mail]>]

On 10/24/2012 08:05 AM, Salvatore Loreto wrote:
> Hi there,
>
> I have updated the draft trying to capture the result of the 
> discussion we had in this mailing list
> writing down for SCTP a <fmt> syntax similar to that used for RTP,
> i.e. with "channle numbers" being used in a way analogous to payload 
> type numbers.
FWIW, I think locking ourselves into this scheme is a Very Bad Idea. It 
will make it impossible to do many of the novel and interesting 
applications envisaged by WebRTC participants.

If you want to have the ability to declare some scoping for SCTP usage, 
I think we should at least:

- Extend the "a=streams" parameter to take a range, including "*" for 
"unlimited".
a=streams:1-* would mean that one expects to use at least 1 stream, but 
no upper limit.
a=streams:0-255 would mean that one may or may not use streams, but 
can't support more than 255.

- Extend the "a=datachannel" syntax to take a default notation, and not 
limit other fields.
a=datachannel:* RTCWeb would then mean that all datachannels not 
explicitly specified will use the RTCWeb protocol, and label and other 
options will be passed using the RTCWeb initialization protocol.

I would like to just hardcode in my browser that it always sends

m=application 1234 DTLS/SCTP 0
a=streams:0-*
a=datachannel:* RTCWeb

and really have SDP O/A stay out of the way of datachannel setup. I 
don't see the need to do more.
But others may have other needs.

>
> The proposal is a very first attempt to see if this is the direction 
> we want to go
> and it is obviously incomplete lacking the possibility to define
> all the properties of the specific channel...
>
> feedback and comments are very welcome and necessary at this point
>
> best regards
> Salvatore
>
>
>
>
> On 10/22/12 10:07 PM, [e-mail] wrote:
>> A New Internet-Draft is available from the on-line Internet-Drafts 
>> directories.
>>   This draft is a work item of the Multiparty Multimedia Session 
>> Control Working Group of the IETF.
>>
>>     Title           : Stream Control Transmission Protocol 
>> (SCTP)-Based Media Transport in the Session Description Protocol (SDP)
>>     Author(s)       : Salvatore Loreto
>>                            Gonzalo Camarillo
>>     Filename        : draft-ietf-mmusic-sctp-sdp-02.txt
>>     Pages           : 13
>>     Date            : 2012-10-22
>>
>> Abstract:
>>     SCTP (Stream Control Transmission Protocol) is a transport protocol
>>     used to establish associations between two endpoints.  This document
>>     describes how to express media transport over SCTP in SDP (Session
>>     Description Protocol).  This document defines the 'SCTP', 
>> 'SCTP/DTLS'
>>     and 'DTLS/SCTP' protocol identifiers for SDP.
>>
>>
>> The IETF datatracker status page for this draft is:
>> https://datatracker.ietf.org/doc/draft-ietf-mmusic-sctp-sdp
>>
>> There's also a htmlized version available at:
>> http://tools.ietf.org/html/draft-ietf-mmusic-sctp-sdp-02
>>
>> A diff from the previous version is available at:
>> http://www.ietf.org/rfcdiff?url2=draft-ietf-mmusic-sctp-sdp-02
>>
>>
>> Internet-Drafts are also available by anonymous FTP at:
>> ftp://ftp.ietf.org/internet-drafts/
>>
>> _______________________________________________
>> mmusic mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/mmusic
> _______________________________________________
> mmusic mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/mmusic