Subject: RE: [Sip] New Resource Priority Draft (-06)

From: "Ken Carlberg" <[email-masked]>
Date: Wed, 2 Mar 2005 14:04:06 -0500

Some minor minor nits...

o Section 1 Introduction: (9'th full paragraph)

 >is busy.  The 'Priority' header field does not affect the usage of
 >GSTN gateway or proxy resources, for example.  In addition, any User
 >Agent Client (UAC) can assert any 'Priority' value, while access to
 >resource priority values are subject to authorization.
 
 Only for the sake of clarity, you may want to change "resource priority"
 values in the last sentence above to " 'Resource-Priority' header values"
 as you have done at the start of the 10'th paragraph.  It probably helps
 the reader a bit more in distinguishing the two fields

o Section 3.1 The 'Resource-Priority' Header Field: (end of 2'nd para)

 >There is no protocol requirement that all requests within a SIP 
 >dialog or session use the 'Resource-Priority' header field.  Local 
 >administrative policy MAY mandate the inclusion of the 'Resource-
 >Priority' header field in all requests. Implementations of this 
 >specification MUST allow inclusion to be either by explicit user 
 >request or automatic.

 The last sentence seems to be dangling a bit with the word "automatic". 
 Would it be fair ato assume that your intention was to say 
 "...automatically by SIP entities"?  In any case, a little 
 clarification is probably needed.

o Section 4.3 OPTIONS Request with Resource-Priority (2'nd paragraph)
 
 >Note that according to RFC 3261, proxies reached with a Max-Forwards
 >value of zero answer the OPTIONS request, allowing a UAC to discover
 >the capabilities of both proxy and user agent servers.

 Should the phrase "value of zero answer"  be  "value of zero MAY answer"?

-ken

ps, many thanks for effort in this latest draft

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From: Henning Schulzrinne <[email-masked]>
Date: Wed, 02 Mar 2005 22:31:29 -0500

>  the reader a bit more in distinguishing the two fields

Reworded.

>  clarification is probably needed.

Indeed; wording changed.

>  Should the phrase "value of zero answer"  be  "value of zero MAY answer"?

Agreed; reworded for clarity.

> ps, many thanks for effort in this latest draft

Thanks for your comments.

Henning

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From: "Piers O'Hanlon" <[email-masked]>
Date: Thu, 03 Mar 2005 11:55:54 +0000

Hi,

This draft (06) is looking better - I have a few comments:

1) The explanation of the use Accept-RP in last para of section 3.3
differs from that in section 4.3 (ie. It doesn't mentioned the
inclusion of an Accept-RP hdr in a 420 response)

2) Section 4.3 should probably mention the inclusion of the 'resource-priority' option tag in a "Supported" header in the response.

3) In section 4.4.1 I'm not sure if it's entirely correct to state
that 'proxies do not manage sessions'? Isn't it possible that a proxy may actually implement the preemption?

Thanks,

Piers.

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From: Henning Schulzrinne <[email-masked]>
Date: Thu, 03 Mar 2005 22:19:45 -0500

> inclusion of an Accept-RP hdr in a 420 response)

A remnant of earlier versions; fixed. 420 is just for 'unsupported' and
thus couldn't be returned in 420.

> 
> 2) Section 4.3 should probably mention the inclusion of the
> 'resource-priority' option tag in a "Supported" header in the
> response.

This is standard SIP behavior, but I guess it doesn't hurt to call it out.

> may actually implement the preemption?

I don't see how a proxy can implement preemption. It has no way to send 
a BYE to the preempted session, for example (and does not see any media 
packets).

> 
> Thanks,
> 
> Piers.
> 
> 
> 
> _______________________________________________ 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: "Piers O'Hanlon" <[email-masked]>
Date: Fri, 04 Mar 2005 15:29:29 +0000

> This is standard SIP behavior, but I guess it doesn't hurt to call it out.
Sure.

> a BYE to the preempted session, for example (and does not see any media 
Ah ok - I was thinking about entities in the network that might implement the preemption - strictly one would probably need to use something like a B2BUA?

Piers.

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From: Henning Schulzrinne <[email-masked]>
Date: Fri, 04 Mar 2005 11:04:35 -0500

> Ah ok - I was thinking about entities in the network that might
> implement the preemption - strictly one would probably need to use
> something like a B2BUA?

Yes.