Subject: RE: SIP URLs: phone numbers

From: Pete Cordell <[email-masked]>
Date: Thu, 21 May 1998 12:07:55 +0100

Henning,

When I tried to look at this my thought was to put the type of address
in the field typically occupied by the password so that you would get
something like:

	sip:+123456:[email-masked]

If a password is needed then it could be appended as a parameter at the
end of the URL, as in:

	sip:+123456:[email-masked];password=claudia

Another problem occurs if you want to make a SIP call to somebody with
an e-mail address at a particular server.  For example, connecting to
some one with an e-mail address of [email-masked] via a sip server
at clearing.org would look something like:

	sip:[email-masked]:[email-masked]

My solution to this was to insist that the first @ should be represented
in its escape code form (%40) so you get:

	sip:john.doe%40big-isp.com:[email-masked]

However, the URL resolver would be well advised not to barf on having
two @ signs!

This is not beautiful, but I think it is better than relying on
heuristics like whether the value starts with a + etc.  One reason for
this is that I feel 'telephone' numbers should be fully qualified for
the domain in which they operate.  This may mean that it doesn't have to
be a full international number.  For example URLs that are limited in
scope to a certain location as might be found in an intranet should not
have to be full international numbers.  Also, corporations should be
able to have corporate wide integrated number plans for private networks
that are not necessarily full international numbers.  For example,
apparently I can be reached from any where in my corporation with the
number *71646436.

Regards,

Pete

=================================
Pete Cordell
BT Labs
E-Mail: [email-masked]
Tel: +44 1473 646436
Fax: +44 1473 645499
-------------------------------------------------------------
Notice:  This contribution is the personal view of the author and 
does not necessarily reflect the technical nor commercial direction 
of British telecommunications plc.
=================================

>----------
>From: 	Christian Huitema[SMTP:[email-masked]]
>Sent: 	20 May 1998 18:06
>To: 	Henning Schulzrinne; [email-masked]
>Subject: 	Re: SIP URLs: phone numbers
>
>Henning,
>
>A gateway handling both names and numbers could easily use two
>DNS names, like "[email-masked]" and
>"[email-masked]",
>yet make the two domains synonym (using CNAME).
>
>-- 
>Christian Huitema
>----------
>See you at INET'98, Geneva 21-24,July 98 http://www.isoc.org/inet98/
>

---

From: Henning Schulzrinne <[email-masked]>
Date: Thu, 21 May 1998 16:27:51 -0400

>         sip:+123456:[email-masked];password=claudia

Another possibility is to make use of the parameters, such as

sip:[email-masked];e164

This has the advantage of being compliant with "standard" (mailto,
telnet) URLs.

> However, the URL resolver would be well advised not to barf on having

Email has traditionally approached this problem with addresses like

[email-masked]

or, escaped correctly for SIP,

sip:[email-masked]

-- 
Henning Schulzrinne   [email-masked]
Dept. of Comp. Sci.   ph  +1 212 939-7042
Columbia University   fax +1 212 666-0140
New York, NY 10027    http://www.cs.columbia.edu/~hgs