Re: [MMUSIC] SCTP question: Where does it multiplex?

[Paul Kyzivat <[e-mail]>]

On 12/3/12 6:13 AM, Harald Alvestrand wrote:
> On 12/03/2012 10:02 AM, [e-mail] wrote:
>> Hi,
>>
>> I agree that it would be useful to be able to run data channel on the
>> same 5-tuple as RTP/RTCP, and even making it the default and
>> must-implement way for the browsers.
>>
>> QoS/prioritization comes to mind as the only potential drawback. The
>> endpoint can naturally still give different priorities to the
>> different components (audio, video, "data") it is sending. I assume
>> SCTP also has TCP-style receiver window that can be used to throttle
>> reception if needed. And presumably RMCAT will find solutions to
>> congestion control in genenral. But from the network perspective there
>> is only one flow, and the only(?) way to differentiate the components
>> is to use DSCP. I don't think our QoS (or API) draft yet clearly
>> explains how DSCP's are learned and set, or whether that is even going
>> to be a realistic solution.
>
> That is indeed the only reason I can think of to specify multiple
> m-lines for DTLS/SCTP (and we don't need to bundle them together).
>
> At the moment, the MMUSIC API doesn't define a way to control which
> m-line a DTLS assocation gets mapped onto.

MMUSIC *API*???

Do you mean the SDP signaling for this? (draft-ietf-mmusic-sctp-sdp-02)

It specifies a new m-line format for this.

	Thanks,
	Paul