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From: johns@happy.uk.sun.com (John Slater)
Newsgroups: comp.dcom.telecom
Subject: Re: NANP Codes AND I Want to Dial the Area Code on a Local Call
Message-ID: <8958@accuvax.nwu.edu>
Date: 14 Jun 90 17:28:02 GMT
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Reply-To: "John Slater <johns@happy.uk.sun.com>
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X-Telecom-Digest: Volume 10, Issue 434, Message 8 of 9


In article <8869@accuvax.nwu.edu>, mitel!spock!grayt@uunet.uu.net (Tom
Gray) writes:

>In article <8733@accuvax.nwu.edu> John Slater <johns@happy.uk.
>sun.com> writes:
>X-Telecom-Digest: Volume 10, Issue 418, Message 6 of 10

>>>In a perfect world I could dial "+44 81 676 XXXX" to reach my number
>>>in London from *anywhere* in the world, including the UK (where +
>>>means 010). Similarly it would be nice to be able to dial 011 1 415
>>>XXX XXXX to reach San Francisco from anywhere in the US.

>>>I was originally going to post this with lots of ":-)", but seriously
>>>though folks, why should it be difficult with modern switches?

>The main problem with this proposal would be the size of the data base
>required inside of each switch. Think of the routing problems which
>would occur when any digit sequence could be used to identify a trunk
>route. Each switch would be required to maintain the telephone number
>of all of the subscribers in the world. Even small CDO's would require
>gigabytes of disk storage.

I don't see why this is the case. Surely all the switch needs to know
is its own country and area codes.

Here's an example. Suppose I dial my home number as 010 44 81 676 0694
from a payphone down the street. As soon as it gets the second 4, the
switch thinks "Ah - 01044 means a call to the UK. But I'm in the UK,
so I'll pretend the caller dialled 0 instead. Now we've got 081-676
XXXX.  But I'm in the 081 area, so I'll pretend the caller didn't dial
the code. (This bit already works - I can dial 081-676 XXXX from said
payphone) So what he/she really wants is 676 XXXX". All other country
codes and area codes get passed on as normal.

All the switch has to do is delay passing control onto an
international switch until it has received sufficient digits to check
that the call really needs it.  Why should it be any more complicated
than that?


John Slater
Sun Microsystems UK, Gatwick office