2008/9/23, karthik karthik <[EMAIL PROTECTED]>: > 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?
If you want to implement a PBX you need a B2BUA, not just a proxy. Imagine you want to redirect the call to other destination when the leg ends: - A calls B through a B2BUA. - B sends a BYE. - B2BUA receives the BYE and instead of sending a BYE to A it creates a new leg to C, so A speaks with C. This it not possible with a proxy (even if it's a call stateful proxy). -- Iñaki Baz Castillo <[EMAIL PROTECTED]> _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
