Re: [sipcore] WGLC: draft-ietf-sipcore-name-addr-guidance

[Yehoshua Gev <[e-mail]>]

On Thu, Mar 16, 2017 at 10:46 PM, Dale R. Worley <[e-mail]> wrote:

> Robert Sparks <[e-mail]> writes:
>
> If you form the header and violate the guidance by not using <>, the
> header will necessarily be parsable *by the BNF alone* in the way it was
> constructed.  It might also be parsable by the BNF alone in another
> way.  What the guidance does is resolve the parsing ambiguity by
> favoring the interpretation of comma, etc. as separators in the header
> rather than as characters in the URI.


This is something that I raised some time ago, in this thread
https://mailarchive.ietf.org/arch/msg/sipcore/8DQXMoMSXfvldRYgRu-YcwhfKFo ,
and I'm sorry that I've left it open then.

I still think that the current wording of the draft might be misleading.

The examples of:
   Refer-To: sip:123@host?Replaces=1111
   Refer-To: sip:123@host;user=phone?Replaces=1111
will all be syntactically invalid using the interpretation proposed by the
draft.
I think this is ok and corresponds to my current understanding of RFC 3261.

However, in the above thread, it seemed to me that on first sight, both Dale
and Robert thought that those examples are valid.
After the discussion there, I think (IIUC) they agreed that those are not
valid.

This draft is a great place to state how exactly those type of examples
are parsed.
Also, it might be good to show an example like:
   Refer-To: sip:123@host;user=phone
which is valid, but interpreted with an header parameter although it might
have been intended to have a URI parameter (there is a reference to
section 7.3.1 of [RFC3261], but is it not stated there explicitly regarding
URI).

Thanks,
Yehoshua Gev