[SIPForum-discussion] TAG, BRANCH, CALLID

[Raj Jain]

On Tue, Jun 17, 2008 at 7:38 AM, Sylvester <hi at psylvester.net> wrote:
> Good day, I have a question - what's the difference btw a TAG, BRANCH & call
> ID.?
> Does tab appear in "to" and "from" number? Branch, i have seen in Via
>
> its confusing , if someone can help, that would be great.

Tags are basically identities of the user agents and they appear in To
and From headers. Branch is something that uniquely identifies a SIP
transaction. A lot can be said about the header fields/parameters that
you mentioned. Your best bet is to get familiar with RFC 3261. There
are also some very good books on SIP out there.

--
Raj Jain