On Fri, 2009-05-08 at 11:08 +0530, bharath.rangana...@wipro.com wrote: > Let me make the question very clear. > - There is NO Proxy/B2BUA in between uac & uas. In this scenario can the > uas send 400 response after 180 Ringing. > Because when the UAS generates 180 Ringing, it means that the received > request is correct in terms of syntax(ABNF).
It would be quite foolish to assume that there is no proxy between the UAC and the UAS. Even if there is not one in your system now, there may be one next year. There is no reason to assume that the *only* reason that a 400 response can be generated is due to syntax errors in the request. Similarly, there is no reason to assume that because you have received a 180 response, that there are no syntax errors in the request. Let us make the answer very clear: Yes, you can receive a 400 response after you receive a 180 response (with the same to-tag). Your UAC should do something sensible in this situation. Specifically, it is required to consider that the call set-up has failed and that the early dialog is terminated. Dale _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
