[MMUSIC] BUNDLE and DATA CHANNEL

[Christer Holmberg <[e-mail]>]

[Was: [MMUSIC] Comment on Payload type restriction in draft-ietf-mmusic-sdp-bundle-negotiation-03]

Hi,

> - the draft doesn't currently talk at all about including the
>   m-line for the SCTP association for data channels in the bundle,
>   but people expect it. There is a special mechanism for demuxing
>   those packets from RTP. But that mechanism is limited to SCTP
>   over DTLS. And it is limited to a single SCTP association in the
>   bundle.

That is for sure text that needs to be added - assuming we have a WG decision that we are going to do it. Or, does someone think we only need to care about RTP (as far as BUNDLE is concerned) at this point?

>ISTM that there must be specification of:
>- the demux mechanisms that are available,
>- how they work,
>- how they do or don't coexist with one another,
>- and how they are signaled in SDP.
>
> The list of available demux mechanisms may need to be extensible.
> And the bundle mechanism should be designed to accommodate that.

Yes. Whenever someone wants to add a new transport to BUNDLE, he/she needs to describe how the multiplexing with other transports is done, i.e. fill out the bullet list above.

BUT, does that mean that we need a signalling mechanism where a BUNDLE client inform which demux mechanisms it supports?

        	Example: a=mux_transports: RTP, DTLS-SCTP

In future, someone may specify how to add MSRP to BUNDLE, and how to mux it with DTLS-SCRTP and RTP:

	Example: a=mux_transports: RTP, DTLS-SCTP, MSRP

Regards,

Christer