> > A —> Switch —> B > All 3 nodes connected with SIP connectivity. > A sending INVITE to B but does not contain Require:100REL. Switch forwards > Invite to B but has Require:100REL. > B responds with 180 without SDP, Switch forwards the same to A. B then > sends 183+SDP, which switch sends to A. Then A sends 200OK which Switch > does not forward to A. B sends 200OK multiple times as per standard and > Switch disconnects session at both the ends with SIP cause code 500. >
Hi. I tried to visualize the call flow: A Switch B +-----------> +----------> INVITE INVITE Require: 100rel <-----------+ <----------+ 180 w/o SDP 180 w/o SDP <-----------+ <----------+ 183 w/ SDP 183 w/ SDP <----------+ 200 OK <----------+ 200 OK [...] Your described call flow lacks some details: 1. Does the INVITE contain any SDP? 2. Was the INVITE from Switch to B really send with Require: 100rel? 3. Are there any other SIP-Requests containing either "Supported: 100rel" or "Required: 100rel"? 4. Were there any PRACK-Requests send? 5. Does the 200 OK contain any SDP? BR Philipp _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors