El Jueves, 11 de Diciembre de 2008, Bogdan-Andrei Iancu escribió: > A) contact info versus network info > > When considering a REGISTER request, you have two sets of information: I > - registered contact ; II - network info (source IP/port, proto, local > socket where the request was received on). > When comes to determine the destination for pinging, right now, the > logic uses the network info (as more or less NAT at network level). > But, according to RFC 3261, the REGISTER request may carry whatever > contact, like a REGISTER via UDP may register a contact for TCP (or > vice-versa). In case of NAT, this will not work at all (as we assume > that the source of REGISTER and registered contact point to the same > network location). > > So, the question is: if NAT detected and such a protocol mismatch is > detected, should a registrar refuse the registration (as it will be > anyhow unusable) ?
I've asked in SIP-implementors about *real* usage of registration with a Contact different than the UA sending the REGISTER. I've received some responses and my conclusion is clear: There is NO real usage of if, this is: it makes no sense *at all* that a UAC sends a REGISTER with a Contact differing of his own location. The responses I've received talk about exotic (and 100% useless and unreal) cases. Case: - alice sends a REGISTER with "Contact: sip:[email protected]". This is a kind of forwarding and will work even if alice is behind NAT since when the proxy receives a call for alice it will loop over him and end locating bob AoR. -- Iñaki Baz Castillo _______________________________________________ Users mailing list [email protected] http://lists.opensips.org/cgi-bin/mailman/listinfo/users
