Re: Proposal for SctpTransport (and big picture diagram)

On Jan 24, 2014, at 9:59 AM, Peter Thatcher <pthatcher@google.com<mailto:pthatcher@google.com>> wrote:

I think there can only be one SctpTransport per DtlsTransport at a
time, because I don't know if there is a way to demux multiple SCTP
associations over a shared DTLS connection.  Maybe SCTP port number?
Or non-overlapping SIDs?  But that all sounds like extra complexity
without much benefit.  You could, I think, have different
SctpTransports on top of the DtlsTransport at different times (stop
one and start another), but I'm not sure if there's a good use case
for that.

I'm still getting re-engaged with a lot of the WebRTC/ORTC mailings, but I have (I hope) a fairly simple question -

For ORTC, why is the DataChannel tightly coupled to an SCTP transport?  I can understand why for WebRTC 1.0 compatibility.  That said, given the number endpoints actually capable of sctp (pretty small -- I believe Windows, iOS, and Android don't support it), is there a reason why SCTP is the only transport provided for the DataChannel in ORTC?  I could see a "MUST" for backward compatibility, but has there been discussions about softening that for non-backward compliant implementations?

Thanks
-jim spring