2009/3/3 sarvpriya <[email protected]>: > hello, > I am currently implementing RFC 3263. My SIP application only supports UDP. > I want to know that while sending outgoing requests or responses, if it > fails then alternate address needs to be tried. Can you please give > definition of this "fails"
> 1) it could be transport error ( vat kind of transport error for UDP) Yes. > 2) If i send an outgoing invite and i rcv no response i.e not even 1xx, then > in this sceanrio also do I need to try for alternate address? Yes, sure. Note that in case of not receiving 100, the timer expires in a few seconds. > 3) similarly while sending in dialog request say info, if I dnt get reply to > info, then shud i contact alternate ip addresses? No, when you send an in-dialog request the destination is the remote-target (the other endpoint "Contact" header URI). That URI contains a definitive location, i.e: - sip:[email protected] -> UDP 1.2.3.4:5060 - sip:[email protected]:6666;transport=TCP -> TCP 1.2.3.4:6666 - sip:[email protected]:5082;transport=UDP -> UDP 1.2.3.4:5082 In all these cases there is not (and there cannot be) an alternative address, since the peer you are speaking with has, usually, just one contact address. To your above list you must add: 4) I receive a 503 from my proxy/pbx. In that case if you got destination alternatives when performing the DNS lookup, you must use them. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
