Option 2; and aspects are discussed within rfc5923 section 8.1. RFC 3261 section 17.1.1.2 indicates that the destination address, port, and transport of ACK (for a non-2xx response) MUST be identical to the INVITE.
RFC 3261 section 9.1 indicates that the destination address, port, and transport of CANCEL MUST be identical to the INVITE. > -----Original Message----- > From: [email protected] [mailto:sip- > [email protected]] On Behalf Of Iñaki Baz > Castillo > Sent: Thursday, June 02, 2011 5:04 AM > To: [email protected] > Subject: [Sip-implementors] Proxy receiving a response into its > indicated Via sentby, where to send the ACK > > Hi, let's suppose that a proxy (with public IP) relays an INVITE via > TCP to the UAS. Later the UAS replies 480 but it does it by opening a > new connection to the Via sentby of the INVITE (maybe because the TCP > connection has been broken). > > RFC 3261 allows it, but my question is: where should the proxy send > the ACK? should it use the same TCP connection used for the INVITE > (which is down now)? or could it send it using the new TCP connection > the UAS has opened to send the 480? > > So there are three options (AFAIK): > > 1) Send the ACK using the already broken connection used for the > INVITE (which obviously would fail). > 2) Same as 1 but opening a new connection with the UAS. > 3) Send the ACK using the connection created by the UAS to the proxy > when it sent the 480. > > I expect 2) is the way to go, but perhaps I miss something. > > Thanks a lot. > > -- > Iñaki Baz Castillo > <[email protected]> > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
