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

From: Harald Alvestrand <[email-masked]>
Date: Fri, 02 Nov 2012 11:39:05 +0100

As currently specified, the DTLS/SCTP protocol is carefully specified in 
such a way that it can ride on the same 5-tuple as an SRTP session. I'd 
like to keep that property when we SDP-negotiate it.

The proposed syntax for DTLS/SCTP seems to be

m=<something, likely application> <port number> DTLS/SCTP <fmt data, 
mostly meaningless>

I see two ways to define this as a multiplex:

- Give the same port number as another m= line in the same SDP session
- Give a meaningless port number, and use the a=group:BUNDLE (of 
whatever flavor) to give which port number it's actually multiplexed 
together with.

The best way to do this may be obvious after the BUNDLE discussion, but 
in case there are other considerations .... are there thoughts?

                Harald

---

From: Paul Kyzivat <[email-masked]>
Date: Fri, 02 Nov 2012 10:53:28 -0400

> like to keep that property when we SDP-negotiate it.

It is? How? Where is that specified?

	Thanks,
	Paul

> _______________________________________________
> mmusic mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/mmusic
>

---

From: Harald Alvestrand <[email-masked]>
Date: Mon, 05 Nov 2012 15:55:31 +0100

> It is? How? Where is that specified?
RFC 5764 section 5.1.2 (DTLS/SCTP packets are DTLS packets).