Subject: FW: [Sip] B2BUA

From: Phil Reynolds <[email-masked]>
Date: Tue, 3 Dec 2002 11:00:15 -0000

The problem as I see it is that the RFC defines 2 distinct intermediary
entities a "SIP Proxy" which has limited functionality, i.e. it is not
allowed to modify the body of the message, and a B2BUA which is a full blown
pair of Uas with all the transactional and dialogue stuff.

What we build is something in the middle... We rely on the "real" UAs to do
all the transactions, retries dialogs etc, and we modify the messages and
SDP bodies as they go through.

Personally I don't care what the spec says. We build a system that does a
useful function, if it doesn't fit into a category that is defined by the
spec -- so what? However the marketing types don't quite see it that way ;-)

If the spec is going to define the permissible intermediaries, it SHOULD
allow for things that are not implemented as UAs but externally appear to be
so.

-----Original Message-----
From: Mary Barnes [mailto:[email-masked]] 
Sent: 02 December 2002 16:54
To: 'Phil Reynolds'; [email-masked]
Subject: RE: [Sip] B2BUA

Hi all,

I guess I have to ask, what's the problem with the definition in RFC 3261?