Subject: [sipcore] Review request: Dial String syntax for the "tel" URI Scheme

From: "Zehler, Peter" <[email-masked]>
Date: Mon, 3 May 2010 08:20:24 -0700

All,

This is a request for the list to review an Internet Draft that codifies
the parameters for Dial Strings to be used in an rfc3966 compliant URL.
The requirements for this draft originated in the IEEE/ISTO Printer
Working Group (PWG) <http://www.pwg.org>.  The PWG is a consortium
printer and multi-function device manufacturers, print server
developers, operating system providers and print management application
developers.  Previous works of the PWG include the Printer MIB (rfc3805)
and the Internet Printing Protocol (rfc2911, rfc2910 and others)  The
Working Group in the PWG that I chair is addressing the modeling of
Multifunction Devices.  In that effort an outbound facsimile (i.e.
FaxOut) requires a way to encode Dial Strings in the URL for a
destination facsimile device.

The draft title is "Dial String syntax for the "tel" URI Scheme" and it
can be retrieved from
<http://tools.ietf.org/html/draft-zehler-teldial-info-00>.   It proposes
three "tel" URI schemes parameters that cover pre-dialing, post-dialing
and T.33 subaddressing.  The post-dialing and T.33 subaddressing are
adopted from the now obsolete rfc2806 but updated for tfc3966 syntax.
Pre-dial was created to avoid obfuscation of the resource identified by
the URI.  Rfc2806 allowed the pre-dial string to be included in the tel:
URI.

In a comment on this Internet Draft on the URI Review list it was
suggested that the RAI-area working groups that deals with SIP should be
the place where the Dial String parameter semantics should be discussed.

I look forward to your comments,

Peter Zehler

Xerox Research Center Webster
Email: [email-masked]
Voice: (585) 265-8755
FAX: (585) 265-7441
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701 

> -----Original Message-----

> From: IETF I-D Submission Tool [mailto:[email-masked]]

> Sent: Monday, April 26, 2010 4:06 PM

> To: Zehler, Peter

> Subject: New Version Notification for draft-zehler-teldial-info-00

> A new version of I-D, draft-zehler-teldial-info-00.txt has been
successfully submitted by Peter Zehler and posted to the IETF
repository.

> Filename:        draft-zehler-teldial-info

> Revision:        00

> Title:           Dial String syntax for the "tel" URI Scheme

> Creation_date:   2010-04-24

> WG ID:           Independent Submission

> Number_of_pages: 7

> Abstract:

> The "tel" URI (Uniform Resource Identifier) for Telephone Numbers 

> [RFC3966] describes resources identified by telephone numbers.  These 

> resources specify termination points within a public or private 

> telephone network. The termination points are a globally or locally 

> unique endpoint.  RFC3966 does not address the means by which the 

> telephone URI can be used to reach termination point from a specific 

> node in the telephone network.

> This document specifies the means by which the termination point is 

> reached from a specific node in the telephone network. This document 

> specifies how to encode the numbers, symbols and pauses required to 

> traverse the phone network to reach the termination point in an RFC

> 3966 compliant "tel" URI.

> The IETF Secretariat.

 

Peter Zehler

Xerox Research Center Webster
Email: [email-masked] <mailto:[email-masked]> 
Voice: (585) 265-8755
FAX: (585) 265-7441
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701

---

From: Paul Kyzivat <[email-masked]>
Date: Mon, 03 May 2010 12:29:42 -0400

[with my individual hat on]

Peter,

I find this to be a *terrible* idea!!!

This conflates the notion of a Uniform Resource *Identifier*, with that 
of a Uniform Resource *Locator*.

Were such changes made, it would complicate the use of tel: URIs in SIP, 
and even of sip: URIs, since sip incorporates the telephone-subscriber 
syntax into its own syntax.

For instance, this would confuse URI comparison. Do two URIs that differ 
only with regards to these new parameters compare as equal? For some 
purposes they should, but for others not.

Also, if you have a URI containing these parameters in your address 
book, and share it with me, are those parameters valid for me as well? 
(Most likely I should strip them out, and then perhaps add others in 
their place.)

In sip we eventually defined RFC 4967 to define a way to specify a dial 
string that is distinct from a tel: uri.

If such things are important, I suggest that they belong in a new URI 
scheme. (Or some existing one different from tel:)

	Thanks,
	Paul

P.S. I know there have been other parameters defined for tel: that have 
some of the same issues. IMO that was a mistake. Lets not do it again.

Zehler, Peter wrote:
> three “tel” URI schemes parameters that cover pre-dialing, post-dialing 
> successfully submitted by Peter Zehler and posted to the IETF repository.
> 
>  > 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> sipcore mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/sipcore