Subject: [SIP] CANCEL & Reliability of provisional responses draft

From: Sudipto Mukherjee <[email-masked]>
Date: Fri, 11 Aug 2000 17:30:39 -0400

Hi,

The "reliability of provisional responses" draft mandates that the 
To header in PRACK mirror the "tag", if the provisional response
contained one. Also the PRACK must take the path specified by the
Route header, if the provisional response contained Record-route
headers.

If the UAC needs to send a CANCEL after it has received a 
non-100 reliable provisional response with a to-tag and record-route,

Does the CANCEL still mirror the INVITE being cancelled ?

Or,
Based on the provisional response,
1. Does the CANCEL mirror the "tag" in To header ?
2. Does the CANCEL take the path specified by the Route header ?

Your help in clarifying this issue is appreciated.

Thanks
-- Sudipto

_______________________________________________
SIP mailing list
[email-masked]
http://lists.bell-labs.com/mailman/listinfo/sip

---

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 15 Aug 2000 03:06:54 -0400

> Does the CANCEL still mirror the INVITE being cancelled ?

Yes. That behavior is unchanged. 
> 1. Does the CANCEL mirror the "tag" in To header ?

The To field in the CANCEL is the same as the INVITE.

> 2. Does the CANCEL take the path specified by the Route header ?

No. CANCEL never contains routes.

-Jonathan R.

-- 
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.cs.columbia.edu/~jdrosen         PHONE: (732) 741-7244
http://www.dynamicsoft.com

---

From: Hisham Khartabil <[email-masked]>
Date: Tue, 15 Aug 2000 14:56:50 +0300

> Route header, if the provisional response contained Record-route

"Record-Route is only relevant for 2xx responses and responses where the
server can expect the client to retry for the same call-id, as in
401(Unauthorized) or 484 (Address Incomplete)"  in section 6.33.1

Regards,
Hisham

---

From: Neil Deason <[email-masked]>
Date: Tue, 15 Aug 2000 14:03:31 +0100

> No. CANCEL never contains routes.

Does allowing provisional reliable responses to contain 
Record-Route introduce a slight problem with the wording of 
6.34.2 of the bis? This says that if a UAC finds a Record-Route 
header in any response, it copies it into the Route header of all
subsequent requests within the same call leg. Doesn't that mean
that a Record-Route of provisional response could find it's way
into a CANCEL or is this already explicitly forbidden somewhere 
else?

Maybe the wording of 6.34.2 needs to be:

If a UAC finds a Record-Route header in a final response, it 
copies it into ...                        ^^^^^  

Also as a CANCEL never contains routes there is no reason 
for the Route header to be marked as optional for CANCEL 
in Table 5.

Cheers,
Neil.
-- 
Ubiquity Software Corporation, UK          
http://www.ubiquity.net

---

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 15 Aug 2000 10:43:15 -0400

Neil Deason wrote:
> copies it into ...   

Good suggestion.

> for the Route header to be marked as optional for CANCEL

Also a good idea.

-Jonathan R.

---

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 15 Aug 2000 10:45:06 -0400

> 401(Unauthorized) or 484 (Address Incomplete)"  in section 6.33.1

This is not the case. They are also relevant for reliable provisional
responses, as
specified in:
http://www.ietf.org/internet-drafts/draft-ietf-sip-100rel-02.txt

-Jonathan R.