By the way, we are seeing cases where BYE being used terminating early dialog without requiring reliable 1XX handling (ie no 100rel option, no PRACK) in production environment.
On Wed, Jul 27, 2011 at 1:01 PM, Iñaki Baz Castillo <[email protected]> wrote: > 2011/7/27 Brett Tate <[email protected]>: > > The following are two rfc3261 snippets which indicate that the Contact is > mandatory for dialog creating 18x responses. > > > > Section 12.1: "Dialogs are created through the generation of non-failure > responses to requests with specific methods. Within this specification, > only 2xx and 101-199 responses with a To tag, where the request was INVITE, > will establish a dialog." > > > > Section 12.1.1: "When a UAS responds to a request with a response that > establishes a dialog (such as a 2xx to INVITE)" ... "The UAS MUST add a > Contact header field to the response." > > > And table 2 in page 162 says: > > Header field where proxy ACK BYE CAN INV OPT REG > ___________________________________________________________ > > Contact R o - - m o o > Contact 1xx - - - o - - > Contact 2xx - - - m o o > > > So it says that Contact header is optional (o) in 1XX responses for an > INVITE. > > > However I agree with you, section 12 clearly says that a 1XX response > (which I do know that creates an early-dialog) MUST mirror > Record-Route and contain Contact header. However Table 2 above does > not say it. Strange. > > Anyhow this topic is a source of discussions. IMHO it's bad specified > in the RFC. I remember from other discussions more issues like the > presence of Record-Route and Contact in a 1XX or 2XX response > different than those in a previous 1XX. There are ugly rules for that > specified somewhere in the RFC. > > > Regards. > > > > -- > Iñaki Baz Castillo > <[email protected]> > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
