> I agree with you but <the vendor> does not. > > Basically what they are saying is this: If SDP version number > is incremented then this counts as an update/new offer period.
They can call it whatever they want. RFC 3261 says that the SDP must be ignored (i.e. it is not an updated answer or new offer). However if the vendor wants to disregard the "MUST ignore" and release the call, that is their prerogative. If the other vendor wants to interoperate with them, they will quit making the useless modification to the SDP. For completeness, I'll just say that the offer/answer model typically requires devices support RFC 3262, RFC 3311, and RFC 3261's forking interactions to avoid a poor user experience during call setup. Since there are vendors which still don't support such things (and operators that disable such functionality), devices occasionally have configuration options to intentionally disregard the "MUST ignore" in an attempt to improve the user experience (such as by handling as an updated answer). However, it sounds like there are others that prefer to disregard the "MUST ignore" and choose to release the call. -brett _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
