Subject: [SIP] SIP extensions and the base reference for SIP

From: "Drage, Keith (Keith)" <[email-masked]>
Date: Mon, 26 Feb 2001 23:43:01 -0000

I have been doing some working through the table 4 and 5 in the RFC2543 and
the bis draft, and looking at how the various SIP extensions affect this.

I come to the following conclusions:

i)	when and if the SIP bis draft ever gets accepted as an RFC, we are
going to have to a lot of work (much of it technical rather than editorial)
on the extension drafts to make them reference the bis draft, rather than
RFC2543.

ii)	currently there is potential conflict between some of the extensions
in what they say in terms of the usage of various headers and methods, for
example we have method definitions that apparently say they are special, and
a lot of headers are not required, and header extensions that say the
extensions are appropriate to all methods including ACK.

iii)	there also seems to be some inconsistency in the way the authors of
the various extensions have treated these tables in completing them.

I think some work therefore needs to be done in this area. I would like to
at least propose the following:

-	That all extensions include editor's notes to specify text that can
be removed at IESG review time. This will give additional text or
replacement text that allows the extension to refer to the bis draft rather
than RFC2543, and will allow a ready view of what needs to be updated as and
when the bis draft becomes an RFC.

-	That a volunteer should identify the required extensions or changes
to the INFO method RFC to allow it to refer to the bis draft.

-	That the guidelines document should contain text on how table 4 and
5 should be extended by any SIP extension, particularly in relation to that
SIP extension and any other extension that has already been published or is
in progress. I would note that some extensions which add either headers or
methods do not include the extension material to table 4 and 5, and none of
the extensions which do provide this material indicate what is appropriate
in relation to the INFO header, which is in an extension that is now an RFC.

-	Presumably a sense of honour and spirit of benevolence will then
cause all extension authors to follow these guidelines!!!!!

I would be happy with any different set of actions that allows consistency
between the bis draft and the various extensions when the bis draft gets
published.

I have noted a number of apparent errors in the use of these tables and will
publish these to the list in separate mails.

Comments please.

Keith
Keith Drage
Lucent Technologies
Tel: +44 1793 776249
Email: [email-masked]

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