Subject: Proxy questions

From: Shail Bhatnagar <[email-masked]>
Date: Wed, 23 Feb 2000 04:08:53 -0500 (EST)

These questions have probably been discussed in the past - I will ask one
more time.

1) Does To header have any role in call routing ( from a proxy's 
standpoint) - I mean in determining the next hop.

2) A stateful proxy receives a retransmitted request for which it 
**proxied** a 200 OK recently. Should it re-proxy the 200 OK ?

Thanks,
Shail

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From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 23 Feb 2000 09:12:31 -0500

> standpoint) - I mean in determining the next hop.

Normally, no. When using the registration database, it is the request
URI that is used as a key. The request URI is the entity being addressed
at that particular server, so that is what will generally be used.
However, no one can dictate the logic used by a proxy for determining
how a call should be handled. Certainly its possible that the To field
might be used for some kind of policy decision.

> **proxied** a 200 OK recently. Should it re-proxy the 200 OK ?

No. Retransmissions of 200 OK to INVITE are handled end to end.

-Jonathan R.

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

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From: Shail Bhatnagar <[email-masked]>
Date: Wed, 23 Feb 2000 13:05:26 -0500

Jonathan Rosenberg wrote:

> No. Retransmissions of 200 OK to INVITE are handled end to end.

Yes, but what should the stateful proxy do with this re-transmitted INVITE.
Forward it on or simply drop it and wait for UAS re-transmission logic to
retransmit the 200 OK  or re-send the last provisional it sent upstream.

Thanks,
Shail

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From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 23 Feb 2000 14:00:50 -0500

> retransmit the 200 OK  or re-send the last provisional it sent upstream.

The proxy can either drop it or send it. Its not needed to ensure
reliability. The 200 
retransmissions at the UAS will handle this.

-Jonathan R.