Hi Karthik B2BUA has got its own advantage. Imagine a call where originating side (Say Phone A) mandates a particular feature and the terminating side (Say Phone B) does not have support for that. In that case B2BUA will act as terminating endpoint for Phone A and orginating endpoint for Phone B. So call can be established even if the mandated feature by A is not supported by B.
Mandated feature can be call specific as timer, precondition etc. Thannks Kamal -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of karthik karthik Sent: Tuesday, September 23, 2008 2:50 PM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] why do we need b2bua? Hello, Here is a question which I have for long time. What is the prupose of having B2BUA? I know that the B2BUA changes from tag, callid and maintains a seperate dialog when to tag is received. But why it does change in these headers? Some say it is for security reasons? If yes how is it used for security. We also have NAT for security. Some say it is for manipulation of supplementary services. If yes, cant a statefull proxy handle the services without changing call-id, from tag and to tag? Thanks Karthik Prabhu _______________________________________________ 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
