Atilla, > It was my belief that it is correct to send the 1st INVITE's > ACK to the destination derived from the Contact (in the absence > of RR headers). I also believe that, if proxy wants to > get the ACK, it MUST provide a RR header with itself. > > But someone else believes that the 1st INVITE's ACK should be > sent to the outbound proxy (in the absence of RR headers). > > Who is correct?
Normally, an ACK for 2xx is sent to either the first Record-Route header or Contact from the 2xx. ACK for 3xx-6xx MUST be sent to the same target as the INVITE (i.e. same request URI and same resolved IP address). UAs are allowed to define a "pre-existing route set" (see RFC3261 8.1.1.1), which they may use for out-of-dialog requests (like an initial INVITE). There are UAs that send ~all~ their requests to some outbound proxy, even mid-dialog ones. This violates RFC3261 (section 12.1.2) Regards, Jeroen ----- Original Message ----- From: "Attila Sipos" <[EMAIL PROTECTED]> To: <[email protected]>; <[EMAIL PROTECTED]> Sent: Thursday, April 20, 2006 11:17 AM Subject: Re: [Sip-implementors] Outbound Proxy > > A long time ago I posed a question regarding > when the outbound proxy should be used. > > The (very helpful) answer is below. > > In summary the answer given was: >>> In a practical implementation scenario, a UA will send >>> >>> * the 1st INVITE, >>> * the CANCEL for that INVITE and >>> * all REGISTER requests >>> >>> to the configured out-bound proxy server network >>> address and at the >>> configured out-bound proxy server transport port. > > > Now recently I have been told that the ACK of the 1st INVITE > should also be sent to the outbound proxy. > > The scenario is: > endpointA OB-proxy > INVITE----------> > <-------------100 > <-------------180 > <-------------200 > ACK-----------------------> the ACK destination is the > Contact in the 200. > None of the INVITE responses contain any > Record Route headers. > > > So this is another outbound proxy question.... > > It was my belief that it is correct to send the 1st INVITE's > ACK to the destination derived from the Contact (in the absence > of RR headers). I also believe that, if proxy wants to > get the ACK, it MUST provide a RR header with itself. > > But someone else believes that the 1st INVITE's ACK should be > sent to the outbound proxy (in the absence of RR headers). > > Who is correct? > > Many Thanks in advance, > > Attila > > > Attila Sipos > http://www.vegastream.com > > >>> -----Original Message----- >>> From: Jerry Ipe Thomas [mailto:[EMAIL PROTECTED] >>> Sent: 20 October 2004 07:10 >>> To: Attila Sipos >>> Cc: SIP Implementors Mailing List >>> Subject: RE: [Sip-implementors] Outbound Proxy >>> >>> >>> Hi Attila, >>> >>> If an outbound proxy server is configured for a UA, the >>> 1st outgoing >>> INVITE should go to the out-bound proxy server at the >>> configured network address >>> and transport port. Thereafter, *if and only if* the OB >>> proxy *wishes* to remain >>> in the signaling path, it should "Record-Route" the INVITE >>> when proxying it to >>> the next hop so that all requests/responses within that >>> INVITE-created dialog >>> will traverse that OB proxy. The UA must then handle dialogs >>> as described (in >>> detail) in RFC 3261, section 12 and RFC 3263 (normal UA operation). >>> >>> If the early dialog is to be CANCELed, then the CANCEL >>> must also go to >>> the original INVITE destination, here the outbound proxy, at >>> the same network >>> address and the same transport port. >>> >>> In a practical implementation scenario, a UA will send >>> >>> * the 1st INVITE, >>> * the CANCEL for that INVITE and >>> * all REGISTER requests >>> >>> to the configured out-bound proxy server network >>> address and at the >>> configured out-bound proxy server transport port. >>> >>> Warm Regards, >>> >>> Jerry Ipe Thomas >>> Engineer (R&D) >>> D-Link India Ltd. >>> Software and R&D Center >>> #65, 35th Main >>> 100 ft. Ring Road >>> 2nd Stage, B.T.M Layout >>> Bangalore - 560068 >>> PSTN: +91-80-26788350/1 Ext: 117 >>> Cell: +91-9886442530 >>> >>> >>> -----Original Message----- >>> From: Attila Sipos [mailto:[EMAIL PROTECTED] >>> Sent: Tuesday, October 19, 2004 6:25 PM >>> To: [email protected] >>> Subject: [Sip-implementors] Outbound Proxy >>> >>> >>> >>> Hello all. >>> >>> As fas as I understand, if a UA is configured to use an >>> "Outbound Proxy", the UA will send its requests to the >>> OutBound Proxy. >>> >>> Is this the case for ALL requests? >>> If the Route set says send it somewhere else, should the >>> UA still send the request to the OB Proxy? >>> >>> >>> What about responses? >>> I guess all responses should just go back to the destination >>> indicated by the top Via. Is this correct? Or should responses >>> go via the Outbound proxy too? >>> >>> >>> Regards, >>> >>> Attila >>> >>> >>> >>> >>> >>> >>> >>> >>> > > _______________________________________________ > 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
