Subject: RE: [Sip] Open Issue ID#100 - case sensitivity of URL parameter v alues

From: Wai Wu <[email-masked]>
Date: Thu, 14 Jun 2001 15:07:27 -0400

It would be nice if we all use CI. However, since I do not know what every
one else is doing, I use CI for comparisions, and send CS messages exactly
as the spec dictates.

Wai

-----Original Message-----
From: Jonathan Rosenberg [mailto:[email-masked]]
Sent: Thursday, June 14, 2001 11:00 AM
To: [email-masked]'
Subject: [Sip] Open Issue ID#100 - case sensitivity of URL parameter
values

Folks,

The following is an open issue in bis that I would like to discuss. THe
never ending saga of case sensitivity... Here's the problem:

The rules for BNF state:

"literal"
Quotation marks surround literal text. Unless stated otherwise, the text is 
case-insensitive.

And then looking at the SIP URL:

transport-param = "transport="
( "udp" | "tcp" | "sctp" | "tls" | other-transport)

Note how udp, tcp are in quotation marks. This makes them literal text, so
that 
its case insensitive. But, the matching rules say:

Comparisons of scheme name ("sip"), domain names, parameter names and header

names are case-insensitive,
all other comparisons are case-sensitive.

Here, we are talking about a parameter value. This says its case sensitive. 

So, which is it?

Interpretations appear to be mixed. Technically, the correct answer as
written is that they are CS. The reason is that the BNF says that quoted
values are CI *unless stated otherwise*. Well, we did state otherwise.
However, this is a subtletly that is easily missed.

So, we can either stick with whats written, but clarify by explicitly
pointing to the contradiction with the BNF, or be consistent with the BNF
rules, and make it CI. CS is more efficient, CI is more interoperable. I
suspect most people are doing CI for this.

Input?

-Jonathan R.

---
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com

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