Subject: RE: [Simple] Request URI in NOTIFY

From: Jonathan Rosenberg <[email-masked]>
Date: Thu, 26 Jul 2001 15:46:19 -0400

-----Original Message-----
From: Ngo, Dai (c) [mailto:[email-masked]]
Sent: Thursday, July 26, 2001 3:34 PM
To: 'Jonathan Rosenberg'; [email-masked]
Subject: RE: [Simple] Request URI in NOTIFY

>Jonathan, 
>You're right that I have made an error in stating the question. Here is the

>scenario: 

>A (watcher) subscribes to watch B (the Presentity) 
>
>There is a contact header in the SUBSCRIBE from A: [email-masked]. 
>
>A also has previously registered with a contact, which specified 
>Methods=NOTIFY, i.e. [email-masked];Methods=NOTIFY 
>
>B now needs to send a NOTIFY to A. 
>Which address is to be specified in the Request URI for the NOTIFY: The 
>address in the Contact header of the SUBSCRIBE, or the address with 
>Methods=NOTIFY in the registrar database?

How would B know whats in the registration database for A, who is some
client in some provider on the other side of the planet? We use standard SIP
record-routing techniques. If no proxies record-route, the request URI in
the NOTIFY is from the Contact in the SUBSCRIBE. If proxies record-route,
the request URI in the NOTIFY is the top record-route entry (ie, that of the
proxy closest to B).

-Jonathan R.
---
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com

---

From: Ben Campbell <[email-masked]>
Date: Thu, 26 Jul 2001 15:11:15 -0500

> the request URI in the NOTIFY is the top record-route entry (ie, that of the

What if the contact header in the SUBSCRIBE that A sent actually points 
to a proxy/registrar, which A has registered to point to somewhere else?

For example, A sends a register to the proxy/registrar P with a From: of 
A@P and a Contact: <sip:A&A>;methods=NOTIFY. A then sends a SUBSCRIBE to 
B with a Contact: sip:A@P. It would seem to me that the NOTIFY would go 
via A@P, and get proxied or redirected to A&A (if the absense of a 
record-route, of course.)

I suspect this is the sort of scenario that Dai intended.