Subject: RE: [SIP] SIP URL telephone-subscriber syntax.

From: "Fairlie-Cuninghame, Robert" <[email-masked]>
Date: Mon, 10 Jul 2000 06:43:27 -0700

> Frankly, I thought we solved this problem already several 
> days ago? Why
> invent a kludge that no other URL scheme is using to solve a 
> non-issue?

Henning,

I am glad you have so much faith in everybodys' SIP parsers (both existing
and future implementations) being able to handle a semicolon in the user
part. I, however, am a little more sceptical. Telephone-subscriber is an
important feature for parties concerned but IMO it will only be interpreted
by a small proportion of the UA's & proxy out there. 

Frankly, I would prefer that we used recursive escaping of the tel: over
your solution. It might be a little more difficult to implement but at least
you are not risking interopability with older or simpler SIP parsers. As I
said previously (and John reiterated yesterday in another stream) backward
compatiability is more important than elegance!! I personally will recommend
our gateway does not implement telephone subscriber (as written) because it
risks interoperability with many existing UA's (IMO).

Regards,

Robert.

_______________________________________________
SIP mailing list
[email-masked]
http://lists.bell-labs.com/mailman/listinfo/sip

---

From: Henning Schulzrinne <[email-masked]>
Date: Mon, 10 Jul 2000 11:57:05 -0400

> risks interoperability with many existing UA's (IMO).

I'm disappointed that Nuera decides to go against community consensus
and the spec [assuming it does not agree with your position at the
moment]. I hope that you are not representing the official position of
Nuera.

Bake-offs are designed to test appropriate implementation behavior and
discover whether there is a widespread compatibility issue. We should
make sure that this is included in the bake-off agenda. (Judging from
the last bake-off, this was, in general, a feature that needed more
implementor attention, regardless of the semicolon issue.)

-- 
Henning Schulzrinne   http://www.cs.columbia.edu/~hgs