Re: [sipcore] Feature-tags in the Path header field

Paul Kyzivat <pkyzivat@cisco.com> Fri, 17 September 2010 15:52 UTC

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Date: Fri, 17 Sep 2010 11:52:53 -0400
From: Paul Kyzivat <pkyzivat@cisco.com>
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To: Christer Holmberg <christer.holmberg@ericsson.com>
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Cc: "sipcore@ietf.org" <sipcore@ietf.org>
Subject: Re: [sipcore] Feature-tags in the Path header field
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On 9/17/2010 11:40 AM, Christer Holmberg wrote:

> So, if the idea of carrying feature tags in Path is ok as such, I guess one option would be an RFC which defines feature-param for Path (similar to what 4508 does for Refer-To).
>
> So, the extended Path ABNF may look something like:
>
> Path = "Path" HCOLON path-value *( COMMA path-value )
>
> path-value = name-addr *( SEMI rr-param / feature-param )
>
> (Assuming feature-param fits within the syntax for rr-param)
>
>> The fact that a parameter is defined for use on one header does not automatically usable with any other header. (Unless the two headers
>> share some common definition. For instance, if the definition of rr-param was extended for Route then I believe Path would automatically
>> pick that up as well.)
>
> I agree, and that's why I sent the e-mail to the list :)

OK. That is something that can be discussed.

ISTM that Path is very similar to Route, and defined to work the same.
So either you define what these things mean for Route, or else you have 
to break the linkage and explain why these are appropriate for Path and 
not Route. Also, if they are appropriate for Path, then perhaps 
Service-Route too.

	Thanks,
	Paul