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RE: [Sip] NOTIFY establishes a dialog



Hisham
The reason the Record_Route headers must be sent on the 200 is that the 1xx
is not guaranteed to be delivered, unless they are sent reliably.

I think in the context of the Notify crossing the 200, the arrival of the
200 will establish the Route set for future requests. Each transaction
completes independently.

I am copying in a old message on this subject from the sip list below that
you may find useful - (I think it would have been useful to state this in
the RFC3261).

------------------ Start Of Old Message --------------------------

>  -----Original Message-----
> From: 	Arunachalam Venkatraman [mailto:arunvenk@cisco.com]
> Sent:	Friday, March 23, 2001 3:39 PM
> To:	sip-implementors@cs.columbia.edu
> Cc:	Jonathan Rosenberg
> Subject:	Replace Contact in Route set ?
>
> As per the protocol, the Contact header is added to the end of the Route
header.
>
> Suppose a Record-Route was first received in a message with a Contact C1.
> The UA has built a route set with the Contact C1 at the bottom of the
Route.
>
> If the next request to the UA has a new Contact C2, should C1 in the Route
Set be replaced
> with C2?
>

Yes. And if there was no Contact, don't change anything.

Note that if the next request has new record-routes, those do NOT update the
existing route sets.

-Jonathan R.
---
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
jdrosen@dynamicsoft.com                     FAX:   (973) 952-5050
http://www.cs.columbia.edu/~jdrosen         PHONE: (973) 952-5000
http://www.dynamicsoft.com

---------------------------------End of Old Message ----------------------

-----Original Message-----
From: sip-admin@ietf.org [mailto:sip-admin@ietf.org]On Behalf Of
hisham.khartabil@nokia.com
Sent: Wednesday, March 19, 2003 4:48 PM
To: sip@ietf.org
Subject: RE: [Sip] NOTIFY establishes a dialog


I have a few related questions/comments:

- A 180 response to a request (like INVITE) establishes a dialog. This 180
response carries record-route headers and therefore sets the route-set. The
200 response to the request might also carry record-route headers. The
dialog transitions to confirmed state, but I assume the route-set does not
get updated using the record-route headers in the 200 response since the
dialog is established already. Is this a correct assumption? should the UAS
send record-route headers at all in the 200 if it sent a 1xx already?

Should there be a mandate that 1xx and 2xx response carry the same
record-route headers? You would assume that this happens naturally at the
UAS, but proxies may play around with the record-route headers.

- In the NOTIFY problem below, the NOTIFY establishes the dialog, but does
not carry record-route headers. If the same assumption is made as above, the
record-route headers appearing in the 200 response to the SUBSCRIBE are
ignored since the dialog is in established state. Isn't this a problem? the
route-set is lost.

I appreciate some clarifications.

Regards,
Hisham


> -----Original Message-----
> From: ext hisham.khartabil@nokia.com
> [mailto:hisham.khartabil@nokia.com]
> Sent: Wednesday, March 12, 2003 5:37 PM
> To: sip@ietf.org
> Subject: [Sip] NOTIFY establishes a dialog
>
>
> In RFC3265, it is mentioned that NOTIFY can certainly
> establish a dialog if it arrives before the 200 of a
> SUBSCRIBE. What happens when the 200 for the SUBSCRIBE now
> arrives with record-route headers? Does the route-set get
> updated? (keeping in mind that the dialog is now in the
> established state).
>
> Regards,
> Hisham
> _______________________________________________
> Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
> This list is for NEW development of the core SIP Protocol
> Use sip-implementors@cs.columbia.edu for questions on current sip
> Use sipping@ietf.org for new developments on the application of sip
>
_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors@cs.columbia.edu for questions on current sip
Use sipping@ietf.org for new developments on the application of sip

_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors@cs.columbia.edu for questions on current sip
Use sipping@ietf.org for new developments on the application of sip