Subject: Re: [Sipping] Tags in respones to CANCEL WAS: Re: Question about Section 3.8 ofdraft-ietf-sipping-basic-call-flows-01.txt(Eiji Tomimura)

From: Gonzalo Camarillo <[email-masked]>
Date: Tue, 05 Nov 2002 17:34:28 +0200

Hi,

Let's try to finish this discussion. Summarizing:

Should the 200 OK responses to CANCEL have a To tag?

Reasons for NO:

CANCEL is hop-by-hop, and therefore, 200 OK responses for CANCEL are
also hop-by-hop. If we look at 100 Trying responses, which are
hop-by-hop as well, we see that they do not have a tag.

Reasons for YES:

Final responses to any request have tags. Even non-2xx final responses
for INVITE, which are hop-by-hop, have a tag.

Note that user agents and proxies will have to be prepared to receive
200 OK responses for CANCEL with or without tags anyway, to improve
interoperability. So, this is not a big deal after all. Our decision is
only useful as long as it helps develop a coherent spec.

I would suggest to go for YES, document it, and move on.

Comments?

Thanks,

Gonzalo
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---

From: "Bob Penfield" <[email-masked]>
Date: Wed, 6 Nov 2002 12:51:10 -0500

----- Original Message -----
From: "Gonzalo Camarillo" <[email-masked]>

> Should the 200 OK responses to CANCEL have a To tag?

I say YES. My current interpretation of RFC 3261 is that it is required. I
see no reason to special case CANCEL final responses.

> hop-by-hop as well, we see that they do not have a tag.

CANCEL may be hop-by-hop, but the element sending the 200-OK is always the
UAS for the cancel transaction and the element receiving the 200-OK is
always the UAC for the cancel transaction. That is not the case for a 100
response.

> I would suggest to go for YES, document it, and move on.

I totally agree. Let's move on.

---

From: "Sean Olson" <[email-masked]>
Date: Thu, 7 Nov 2002 00:13:52 -0800

I vote NO. Treating the CANCEL as we do a 100 Trying makes a great deal
of sense.
It is the commonality between the two which helps solidify this
behavior. It also
goes with the branch and CSeq handling for CANCEL (though this is
obviously done for
different reasons). But as pointed out, it really doesn't matter what is
decided, an
implementation should be prepared to receive either.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Bob Penfield
Sent: Wednesday, November 06, 2002 9:51 AM
To: Gonzalo Camarillo; Jonathan Rosenberg
Cc: Jiri Kuthan; Jiri Kuthan; manoj mallik; [email-masked];
[email-masked]; [email-masked]
Subject: Re: [Sipping] Tags in respones to CANCEL WAS: Re: Question
about Section 3.8 ofdraft-ietf-sipping-basic-call-flows-01.txt(Eiji
Tomimura)

----- Original Message -----

> Should the 200 OK responses to CANCEL have a To tag?

I say YES. My current interpretation of RFC 3261 is that it is required.
I see no reason to special case CANCEL final responses.

> hop-by-hop as well, we see that they do not have a tag.

CANCEL may be hop-by-hop, but the element sending the 200-OK is always
the UAS for the cancel transaction and the element receiving the 200-OK
is always the UAC for the cancel transaction. That is not the case for a
100 response.

> interoperability. So, this is not a big deal after all. Our decision 
> is only useful as long as it helps develop a coherent spec.
>
>

> This list is for NEW development of the application of SIP Use 
> [email-masked] for questions on current sip Use 
> [email-masked] for new developments of core SIP
>

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

---

From: "Vijay K. Gurbani" <[email-masked]>
Date: Thu, 07 Nov 2002 08:58:50 -0600

[...Trimmed the CC list...]

>Should the 200 OK responses to CANCEL have a To tag?

I would vote YES.

A 200 OK (CANCEL) is NOT a provisional response; it is a
final response to a request (hop-by-hop status of CANCEL not-
withstanding).  As such, I don't see why it shouldn't have a tag.

- vijay
-- 
Vijay K. Gurbani  vkg@{lucent.com,research.bell-labs.com,acm.org}
Wireless Networks Group/Internet Software and Services
Lucent Technologies/Bell Labs Innovations, 2000 Lucent Lane, Rm 6G-440
Naperville, Illinois 60566     Voice: +1 630 224 0216