2011/7/6 Olle E. Johansson oej@edvina.net:
Also, I've already make a question previously: you say that "transport=tls" is correct, so is "tls-sctp" also correct? RFC 4168 (SIP over SCTP) defines "SCTP" and "TLS-SCTP" for Via transport, similar to "TCP" and "TLS" (which means TCP over TLS). But RFC 4168 does not define "tls-sctp" for an URI transport param. Why not? because the correct way is "sips" schema and ";transport=sctp".
THis is defined according to RFC5630: For Via header fields, the following transport protocols are defined in [RFC3261]: "UDP", "TCP", "TLS", "SCTP", and in [RFC4168]: "TLS- SCTP".
Transport in Via header and transport in SIP URI header are different things. In the RFC 3261 BNF they appear as different elements. The fact that some values match doesn't mean that are equivalent in both sides.
Said that, this stuf becomes more and more complex due to this fact: this is: Via transport accepts "TLS" or "TLS-SCTP" while ;transport does not.