Subject: Re: [Iptel] comments on rfc2806bis - unique prefix

From: [email-masked]
Date: Tue, 19 Nov 2002 17:55:52 EST

In a message dated 11/19/2002 1:17:27 AM Eastern Standard Time, 
[email-masked] writes:

> > A global number prefix consists of the initial digits of a valid       |
> >    global number. When a global number prefix is used as the context, it  
> |
> >    MUST be chosen to be unique. 
> 
> unique across what?
> 
This has been an issue in some previous discussions - how to "guarantee 
uniqueness" if each potential end user decides on their own value of "global 
number prefix"? If this uniqueness is critical to the operations that use the 
tel:uri, then there should be some rigid scheme for the user to pick the 
value, or else an IANA registration process. I really can't imagine an IANA 
registration process here.

Note that the ABNF does not define a "global number prefix" but rather a 
context which may consist of a "global-number-digits" which is a "+" plus 
some number of digits. (The + is a little out of place here, since what 
follows may not be a full E.164 address. The ABNF doesn't even restrict it to 
being the first so many digits of a E.164 number.)

Originally I thought that this "global prefix" was something that could be 
concatenated with the "local number" to form a full E.164 number. Since that 
is not true, it does not have to be a "prefix" of anything. It simply must be 
unique, and could be any digit string desired. There simply must be a way to 
define the rules for assignment. I thought we had arrived at some text to say 
that the user must select a "prefix" of the E.164 number, such that they are 
assigned every possible E.164 number beginning with that "prefix". The 
alternative would be to say that the context (if not using the domain-name 
scheme) must contain a full E.164 number (any one assigned to and choosen by 
the user) to represent its "domain".

Mike Pierce
Artel