From an implementation perspective, what is the difference between a
SIP B2BUA and a Proxy Server (especially Stateful Proxy Server)?
According to http://www.b2bua.org, the difference between a SIP B2BUA
vs Proxy Server is as follows:
"Unlike a SIP proxy server, which only maintains transaction state,
the B2BUA maintains complete call state and participates in all call
requests. For this reason it can perform number of functions that are
not possible to implement using SIP proxy, such as for example
accurate call accounting, pre-paid rating and billing, fail over call
routing etc."
Does this mean that the B2BUA should have all the logic that normally
resides in a terminal device? After all, it is two UAs back to back.
I don't see much description for B2BUA in RFC3261.
Is the above description correct?
Thanks,
Song