Subject: [Sipping] Brian's Comments on draft-mahy-sipping-user-equals-

From: "Rosen, Brian" <[email-masked]>
Date: Mon, 20 Oct 2003 10:45:41 -0400

This document is a start, but in my opinion not enough.

The introduction must define dial strings, and differentiate them
from local phone numbers.  It should introduce the idea that a
proxy in the listed domain of a dial string must translate to a global
or local number, and that some phones will do this translation
themselves while others will not.

Section 5 inadequately deals with dial strings.  Dial strings are not
local numbers, and must be translated to local numbers.  One must
disambiguate dial strings from local numbers because it is possible that
they collide.  Such a differentiation is also useful to know when
translation has been completed.

It has been proposed to use separate contexts for dial strings and
local numbers.  I generally don't like this idea, but it can be made
to work.  It would be best if there was some kind of naming convention
to differentiate, but this is not strictly necessary.

What is necessary is text in a document:
	1. Saying that dial strings aren't local numbers
	2. Permitting dial strings in a sip uri, with a dial string context.
		Note: if you wish to permit a dial string in a tel uri, then
                 the language in 2806bis must be modified, IMO.
	3. Explicitly defining the use of E/F
	4. Illustrating the use of separate contexts for dial strings
	5. Discussing the provisioning implications of having two
		local contexts, one for phones with translation and
		another for phones without translation

It would be much more satisfactory, in my opinion, to simply define
user=dialstring, or something similar, to denote that the user part is
a dial string.  Note that sip phones that presently put dial strings in
a sip uri without a context must change anyway.

We also should define a way to express a dial string with pauses and waits.
They are pretty useful. They are dialable in many gateways.  We need
a way to send such a string.  Again, we need text, and again, we could
use a separate context for such strings.

I do agree with the draft's concepts that
	user=phone indicates a local or global number as defined by 2806bis
	user=phone without a context on a local number is deprecated

As before, I will write text when we agree we want text to cover.
Thanks to Rohan for this good start.

Brian

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---

From: Rohan Mahy <[email-masked]>
Date: Mon, 27 Oct 2003 16:24:20 -0800

On Monday, October 20, 2003, at 07:45 AM, Rosen, Brian wrote:

> from local phone numbers.

I think this is the crux of the disagreement.  I don't think it is 
possible to give a rigorous definition of what is a dial string and 
what is a local number.  I invite you to describe an algorithm you can 
use to determine which is which.  If you can then I'll incorporate it 
in the draft, but I am skeptical that such a distinction is testable 
any more than the distinction between "erotic art" and "pornography".

>  It should introduce the idea that a

i don't think they can collide because they are in different contexts

> 		another for phones without translation

I thought I covered this last one a bit in the draft. A phone that 
doesn't know its context can just use *itself* as the context.  That 
requires no configuration.  A phone that has a digit map obviously 
needs to be configured with it, so explicitly setting the target 
context or domain (or both) should be no problem IMO.

> 	user=phone without a context on a local number is deprecated

cool.  I'm very happy about that.

> Thanks to Rohan for this good start.

thanks for your comments.
take care,
-rohan