Subject: RE: Lexical indeterminism in SIP grammar.

From: Eric Tremblay <[email-masked]>
Date: Thu, 1 Apr 1999 13:30:33 -0500

Jagdeep,

If I understand your problem correctly, it *was* solved by a comment found
at the end of section 6.13 in the last *DRAFT* but the solution was removed
from the RFC. (why?)

The comment found in the draft was the following:
   Even if the "display-name" is empty, the "name-addr" form MUST be
   used if the "addr-spec" contains a comma, question mark, or
   semicolon.

This same comment can be found in section 6.37 in the RFC.

I guess the authors will have to clarify this point...

Eric

Eric Tremblay, ing. stag.
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Mediatrix Telecom
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-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, April 01, 1999 11:39 AM
To: [email-masked]
Subject: Lexical indeterminism in SIP grammar.

I have encountered a case of lexical indeterminism in the SIP grammar. This
was in the
case of the "Contact" parameter (Section 6.13 of draft-ietf-mmusic-sip-12).
As per the EBNF
notation, a legal construct would have been,
Contact = "Contact" ":" SIP-URL *(";" contact-params)
                                           ^^^^^^^^ From addr-spec.
>From Section 2 of the same document, a  valid construct would be
SIP-URL= "sip:" hostport *(";" url-parameter) giving us

Contact= "Contact" ":" "sip:" hostport *(";" url-parameter) *(";"
contact-params)

Cause of the conflict other-param (from url-parameter) and
extension-attribute (from contact-params) which allow String "=" String.

Could someone please explain.

Regards,
Jagdeep Rao.