Hello all, I have a question concerning the interoperability of the SDP Offer/Answer Model from RFC 3264 with the old SIP RFC 2543:
The scenario in question is as follows: UA 1 implements RFC 3261 and 3264 UA 2 implements the old RFC 2543 1) UA 1 and UA 2 establish a call with one media stream 2) UA 1 puts the media stream on hold by marking the stream as "sendonly". 3) UA 2 answers but the answer does not include any direction attribute In my understanding, according to RFC 3264, section 5.1, end of first paragraph: ------------------------------------------------------------------ If the offerer wishes to both send and receive media with its peer, it MAY include an "a=sendrecv" attribute, or it MAY omit it, since sendrecv is the default. ------------------------------------------------------------------ a missing direction attribute has to be interpreted as "sendrecv". However, this would mean that the answer from UA 2 violates RFC 3264, section 6.1, second paragraph: ------------------------------------------------------------------ If a stream is offered as sendonly, the corresponding stream MUST be marked as recvonly or inactive in the answer ------------------------------------------------------------------ Does that mean that the new and old Offer/Answer Model are not interoperable with respect to putting a stream on hold? If so, what is the recommended approach to deal with this? Or is this rather a bug in UA 2 because it should(?) leave all unknown SDP lines untouched? Thanks in advance! Regards, Peter _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
