Subject: RE: [IPTEL] I-D ACTION:draft-ietf-iptel-trip-02.txt

From: James Yu <[email-masked]>
Date: Mon, 5 Jun 2000 21:53:10 -0500

> 
> From TRIP's perspective all numbers/prefixes it advertises are routing
> numbers, otherwise these numbers/prefixes should not have 
> been injected
> into TRIP in first place. This has been stated clearly in 
> Section 11 of
> the "Framework for Telephony Routing over IP" draft. It says: "Since
> TRIP is a routing protocol, the routes it propagates should be to
> routable numbers, not to names which are eventually translated to
> routable numbers."
> 

I'm glad to see that this particular point (roting number vs. subscriber
number) has been clarified in the TRIP document.   Thanks for pointing that
out.  May be that statement should be put in the abstract to make that point
clear.

> > 
> > In the North America, the network routing numbers are 
> called Location
> > Routing Numbers (LRNs).  They "look" like subscriber phone 
> numbers (e.g.,
> > the same length) and can overlap with the subscriber phone 
> numbers.  In some
> > European countries, special digit (e.g., A and B) are used 
> to differentiate
> > the network routing numbers from the subscriber phone 
> numbers.  Those
> 
> I think TRIP should be extended advertising these European formats. Is
> this an extended form of E.164, or should it be a separate address
> family?

Some of the routing numbers (or routig prefixes, as they are usually
prefixes to the dialed called party number) contain the digits outside 0-9
(e.g., A, B, C, D, E, and F).  They are valid routing numbers (national
numbers) either within one network (used by a particular network) or between
networks.  Since they don't just contain digits 0-9, we may not say that
they follow E.164 format.  But they should be viewed as valid routing
numbers.  In this case, a valid digit in a routng number can be from 0
(0000) to F (1111).  After adding the country code to the routing numbers in
Europe, those "international" routing numbers probably can be used for
routing.  The country code will allow the call to be routed to that country.
After removing the country code by a gateway at that country, the "national"
routing number can then be used for routing.  

Since the routing number is cancatenated with the dialed called party number
(they are carried in the Called Party Number paramter)in some NP
implementations in Europe, the "routing number" we are discussing should be
limited to the "routing number" or "routing prefix" instead of the "routing
number + dialed called party number."   For example, UK uses "5xxxxx" as a
routing number/prefix where "xxxxx" identifies the carrier.  A carrier can
assign additional numbers after "5xxxxx" which can point to a network, a
switch/exchange, or even a line card at a switch/exchange.  In that case,
"5xxxxx" plus the "addtional digits" would be treated us the routing number.
I believe that this routing number is not longer than 15 digits. 

Any comment from people in Europe?

> 
> Is there a reason that prevents expanding routing numbers to 
> full E.164
> numbers before injecting them into TRIP?
> 

If "5xxxxx+x....x" is treated as a routing prefix (no exception within the
range), then there is no need to expand a routing number to full E.164
numbers.  In some countries, the E.164 numbers have variable length of
digits.  They don't have a fixed length of digits (in North America, we have
11 digits for all "international" NANP numbers).

James

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---

From: Jonathan Rosenberg <[email-masked]>
Date: Thu, 08 Jun 2000 17:37:57 -0400

James Yu wrote:
> they follow E.164 format. 

Oh yuck.

I'm curious how this impacts the aggregatability of such numbers? Are
they assigned in such a way that they can still be aggregated even
though there are these random letters in the phone number? Is there any
kind of hierarchy in these numbers?

-Jonathan R.

-- 
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
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