>>SIP UA >>Alice------------->Proxy--------------->SIP gateway------------>some network------>Bob >> >>The call gets established. Alice talks to Bob. >>Then Bob transfers the call to Carol.
Let me be clear. Carol is also on "some network". -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Attila Sipos Sent: 10 March 2011 09:19 To: Jyoti Singhal Cc: sip-implementors@lists.cs.columbia.edu Subject: Re: [Sip-implementors] Significance of different PAID headerinRe-INVITE Yes because it's telling one of the parties that the other party is someone else. Say you have this... SIP UA Alice------------->Proxy--------------->SIP gateway------------>some network------>Bob The call gets established. Alice talks to Bob. Then Bob transfers the call to Carol. You would then expect something like an UPDATE or re-INVITE with a new P-Preferred-Identity going from SIP gateway to proxy. Incidentally, RFC 4916 (which is maybe a better solution) also tries to solve the same problem. The scenario I have described above is the same kind of problem as described in RFC 4916's introduction: o the identity of a user that replaces the caller or callee following a call rearrangement such as call transfer carried out within the PSTN or within a back-to-back user agent (B2BUA) using third party call control techniques. ________________________________ From: Jyoti Singhal [mailto:jyoti.na...@gmail.com] Sent: 10 March 2011 08:58 To: Attila Sipos Cc: sip-implementors@lists.cs.columbia.edu Subject: Re: [Sip-implementors] Significance of different PAID header inRe-INVITE But once a dialog is established between two parties, does a change in its PAID header has any significant for the other party? With Regards, Jyoti On Thu, Mar 10, 2011 at 11:49 AM, Attila Sipos <attila.si...@vegastream.com> wrote: I my experience it means that the identity of the connected party has changed. say you have a SIP gateway to some non-SIP network. If a transfer occurs inside the network then the SIP endpoint could become connected to a different user. The SIP UA will update the P-Preferred-Identity from RFC 3325: 9.2 The P-Preferred-Identity Header The P-Preferred-Identity header field is used from a user agent to a trusted proxy to carry the identity the user sending the SIP message wishes to be used for the P-Asserted-Header field value that the trusted element will insert. LATER IN THE SAME SECTION... It is worth noting that proxies can (and will) remove this header field. Then I think the proxy will remove P-Preferred-Identity and replace it with a P-Asserted-Identity to propagate the new identity. From RFC 3325: 9.1 The P-Asserted-Identity Header The P-Asserted-Identity header field is used among trusted SIP entities (typically intermediaries) to carry the identity of the user sending a SIP message as it was verified by authentication. LATER IN THE SAME SECTION... It is worth noting that proxies can (and will) add and remove this header field. regards Attila -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu on behalf of Jyoti Singhal Sent: Thu 10/03/2011 05:29 To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] Significance of different PAID header inRe-INVITE Hi All, I need to know is there any significance of a modified PAID header in Re-INVITE. With Regards, Jyoti _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors . _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
