Subject: Update of 'Contact' address

From: "Ravandhu Hariram" <[email-masked]>
Date: Tue, 14 Mar 2000 12:58:11 -0600

After a call is fully connected between two user agents, if one user agent sends
a new INVITE request with a different 'Contact' address, should the receiving
user agent update its 'Route' header with this modified 'Contact' address?

Thanks,
- hariram

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From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 15 Mar 2000 03:52:34 -0500

> user agent update its 'Route' header with this modified 'Contact' address?

I think so. There are a few applications of this, including mobility and
a few call services. Note, however, that updating of the Route with new
Record-Route headers is different. RFC2543 forbids (I think) insertion
of Record-Route headers when a Route is already there.

-Jonathan R.

-- 
Jonathan D. Rosenberg                       200 Executive Drive
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From: Robert Sparks <[email-masked]>
Date: Thu, 23 Mar 2000 10:15:56 -0600

> of Record-Route headers when a Route is already there.

That restriction has been removed in the bis draft. In fact, the
new language

  "Note that proxy servers have to add Record-Route headers to each
   request as long as they want to be “visited” by the next request
   for the call leg."

can (and I argue should) be interpreted to mean that if a proxy
wants to stay in the path, it should add a Record-Route to
every request. In other words, the effect of Record-Route
is to ensure that the _next_ request from any participant comes
through this proxy.

RjS