2008/7/7 <[EMAIL PROTECTED]>: > From: =?utf-8?q?I=C3=B1aki_Baz_Castillo?= <[EMAIL PROTECTED]> > > Hi, imagine a request from NAT received by a UAS with publi IP: > # INVITE from 80.80.80.80:5060 Via: SIP/2.0/UDP sip:192.168.0.100:5060 > > You mean: > > INVITE 80.80.80.80:5060 > Via: SIP/2.0/UDP sip:192.168.0.100:5060 > > as there is no "from" in an INVITE.
No no, I mean "INVITE from 80.80.80.80:5060" with the following Via: Via: SIP/2.0/UDP 192.168.0.100:5060 I don't care now the RURI. > The UAS converts t to: > Via: SIP/2.0/UDP sip:192.168.0.100:5060;received=80.80.80.80 > > Now imagine the UAS replies a 404 but gets an ICMP error, so it must > perform: > > Your description leaves out many important details. > > I assume that you mean "The UAS constructs a 404 response, but upon > sending it to 80.80.80.80:5060 the UAS receives an ICMP error." Ok. > You ask > > Isn't it a problem in some way? > > Yes, of course, because it doesn't work. > > Presumably this is because either (1) your NAT isn't receiving packets > on the same address/port that it is sending on, or (2) the UAS doesn't > add the rport parameter to the Via when receiving requests (RFC 3581). No no, all is OK, there is no problem of "rport" and so. The only problem could be in a buggy or wrong configured router that doesn't keep open an UDP port to receive responses, so the first reply would fail with ICMP error. But then, the UAS MUST examinate the "sent-by" (192.168.0.100:5060), perform DNS resolution for 192.168.0.100:5060 (that it's obviously the same IP and port) and send there the failover reply. And this second reply would fail since it would be to a unreachable IP (since 192.168.0.100 is the private LAN of the UAC). That's what I mean. Regards. -- Iñaki Baz Castillo <[EMAIL PROTECTED]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
