________________________________________ From: [email protected] [[email protected]] On Behalf Of Nitin Kapoor [[email protected]]
UAC(SIP) -----> Invite/without SDP ------> B2BUA -----Invite/with SDP default port-----> UAS(SIP) Here is what happening at my case that my source UA is sending me invite without SDP to my SBC and my SBC is forwarding the same to termination UA with default port as per the design. But from Termination side I am getting first 183 w/o SDP and others 2 with SDP before getting 200 OK w/ SDP in the correspondence of initial offer INVITE. And in those 183 I am getting “100rel” in REQUIRE header field which is not correct according to me. Because my understanding says that in those scenario where you are getting initial OFFER w/o SDP, PRACK should be not be negotiate before getting the 200 OK w/ SDP for the initial invite. Hence I am facing the media issue. _______________________________________________ Given that your B2BUA is not negotiating the SDP in the same way one each side, it will probably need complex logic to arrange media successfully. But that is not the problem here. It appears that on the termination side, the UAS is behaving correctly regarding which responses contain SDP. In regard to "Require: 100rel" in responses from the UAS, it is allowed to do that if the INVITE to the UAS contained "Supportd: 100rel". Although 100rel is not particularly useful if the 1xx response does not contain SDP, the UAS is permitted to invoke it in those circumstances. SIP is a set of features which each has a defined meaning and which a UA can combine in many ways. In this case, 100rel and SDP negotiation are independent features. Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
