Subject: Query on matching requests to responses at the proxies

From: Sunitha Kumar <[email-masked]>
Date: Mon, 13 Mar 2000 20:33:11 -0800

How do we match requests to responses at the proxies.( other than the
branch in the Via);
using preferably the fields in a CallLeg, ( so that the call can be
uniquely identified).

Ex: responses to 2 INVITES
Is it legal for the proxy to tag the from field of every request that it
forwards or proxies on, and remove the From tag, when the response to
that comes back, before passing it  downstream.  Making sure, that each
proxy on the way, adds itself to the record route.  So, they are
traversed on the way back.

on other thoughts, what about incrementing the CSeq for every request
that goes out, and decrementing the CSeq , when the response for that
arrives, before passing it downstream.

Any thoughts will help. Thanks much!

--
Sunitha Kumar
Software Engineer
Vovida Networks
(408) 957 - 6374

---

From: Jonathan Rosenberg <[email-masked]>
Date: Mon, 13 Mar 2000 23:34:58 -0500

Sunitha Kumar wrote:
> Is it legal for the proxy to tag the from field of every request that
> it forwards or proxies on, and remove the From tag, when the response
> to that comes back, before passing it  downstream.  Making sure, that
> each proxy on the way, adds itself to the record route.  So, they are

Why do this? You'll break authentication and it won't work if a tag was
already there.

> arrives, before passing it downstream.

I also highly recommend against this. If the client sends a request with
that same CSeq, which does not pass through your proxy somehow, things
will be mightily confused. Also this doesn't work with authentication.
Why do you want to do this? The spec is quite clear on how responses are
matched to requests. Why does incrementing the CSeq help in any way?

-Jonathan R.

-- 
Jonathan D. Rosenberg                       200 Executive Drive
Chief Scientist                             Suite 120 
dynamicsoft                                 West Orange, NJ 07052
[email-masked]                     FAX:   (732) 741-4778
http://www.cs.columbia.edu/~jdrosen         PHONE: (732) 741-7244
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