Subject: [SIP] Interworking Between SIP/SDP and H.323

From: "Fairlie-Cuninghame, Robert" <[email-masked]>
Date: Thu, 1 Feb 2001 17:54:12 -0800

Hi Henning & Kundan,

I have a query with regards to draft-singh-sip-h323-01.txt.

The draft states that the destination information from the H.323 call be
derived from the To URL in a new INVITE (see A.1.2). It seems that the
request-URI is ignored entirely (despite the fact that some of the call
flows are annotated with "INVITE sip:[email-masked]").

I do not see how this will work when a SIP UA or proxy redirects (or proxies
with updating the request) call to a H.323 device. 

For example: 

INVITE sip:[email-masked] SIP/2.0
To: "Robert Fairlie-Cuninghame" <sip:[email-masked]>

is sent to the proxy at nuera.com which responds with a SIP/2.0 302 Temp
Moved
Contact: <sip:[email-masked];maddr=h323-iwf.nuera.com>

How will this work if the IWF ignores the Request-URI ?

If the IWF instead uses the request URI in the H323 SETUP destinationInfo,
is there anythign wrong with it using the display name from the To? Unless a
380 Alternate Service is issued then the display name should still be
correct.

On a related note in the base SIP spec, if a 380 Alternate Service is issued
(which requires user interaction), the spec needs to be clarified whether
the new call attempt will use a new call-leg with the To field changed
apprpriately.

Cheers,

Robert.

---

From: Kundan Singh <[email-masked]>
Date: Fri, 2 Feb 2001 13:21:05 -0500 (EST)

> request-URI is ignored entirely (despite the fact that some of the call

This is an error. The signaling gateway should use
the Request-URI instead of To: URL. This occurs at more than
one place in the draft.

We will correct this in the next version.

Thanks for pointing out the mistake.

Kundan

> the new call attempt will use a new call-leg with the To field changed

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