Subject: [Sip] Question about Section 12.2 Requests within a Dialog

From: Ofir Arkin <[email-masked]>
Date: Wed, 27 Feb 2002 18:48:17 +0000

"Requests within a dialog MAY contain Record-Route and Contact header 
fields. However, these requests do not cause the dialog's route set to 
be modified, although they may modify the remote target URI".

First Question:
When a UAS produce a reply to a request within a dialog will it use the 
via to route back to the sending UA or will it consult its 'state' and 
grab the route from there?

Second Question:
Why this might change the target URI?
I must admit that the target refresh thing got me really confused...

Thanks!
-- 
Ofir Arkin
Managing Security Architect
@stake, Limited.
http://www.atstake.com
email: 
[email-masked]
Tel: 
+44 (0) 207 495 7002
Fax: 
+44 (0) 207 495 7062
Mobile: +44 (0) 779 630 8632	

-----------------------------
The information transmitted is intended only for the person or entity to 
which it is addressed and may contain confidential and/or privileged 
material.  Any review, re transmission, dissemination or other use of, 
or taking of any action in reliance upon, this information by persons or 
entities other than the intended recipient is prohibited.  If you 
received this in error, please contact the sender and delete the 
material from any computer.

_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip

---

From: Robert Sparks <[email-masked]>
Date: 27 Feb 2002 13:14:55 -0600

> grab the route from there?
Responses always return following the Via stack.
> I must admit that the target refresh thing got me really confused...

This mechanism allows an endpoint to change the URI it wants to be
handed in future requests within this dialog. This can be used as a
place to store state for future requests. The original proponents 
planned to use this as part of the mechanics to deal with mobility
(address mobility in particular). I don't believe those ideas have
been fleshed out.

---

From: Ofir Arkin <[email-masked]>
Date: Thu, 28 Feb 2002 17:15:23 +0000

What 'state' information does this change?
For example if I send a Re-INVITE within a dialog what 'state' 
information will the Re-INVITE change?

---

From: Jonathan Rosenberg <[email-masked]>
Date: Thu, 28 Feb 2002 12:49:29 -0500

> information will the Re-INVITE change?

The re-INVITE changes the remote URI.

Here is an example. I send an INVITE with a Cotnact header of
sip:<my-piece-of-state>@<my-FQDN>. The call is established. A BYE,
re-INVITE, or other mid-dialog request will arrive to me with this URI
in the request URI. I can use that for whatever purposes I like. If I
wish to change it, I can issue a re-INVITE, which updates it at the
other side.

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

---

From: Gonzalo Camarillo <[email-masked]>
Date: Thu, 28 Feb 2002 19:51:44 +0200

It will change the last hop (the target) for the route of the dialog.

Gonzalo

-- 
Gonzalo Camarillo                    Phone :   +1 212 939 71 71
Columbia University                  Mobile:  +358 40 702 35 35
472 Computer Science Building        Fax   :  +358  9 299 30 52
1214 Amsterdam Ave., Mail Code 0401  http://www.hut.fi/~gonzalo
New York, NY 10027                   
USA                              [email-masked]

---

From: Ofir Arkin <[email-masked]>
Date: Thu, 28 Feb 2002 21:58:46 +0000

So, there is no way to change other state information other than the 
last hop (target URI)?

Ofir

---

From: Gonzalo Camarillo <[email-masked]>
Date: Fri, 01 Mar 2002 00:10:45 +0200

Hi,

That's right. The only thing that you can change in the target... well,
if you consider the local and remote cseqs as pieces of state as well,
they change in every request.

Gonzalo