IPv6 news

Tue Oct 18 11:55:01 UTC 2005

On Tue, 18 Oct 2005, Andre Oppermann wrote:

> We don't want them involved in Internet routing, do we?

Which, POTS telco's or ComReg? :) The latter does a good job afaict.

> Do you have any idea how this works internally?  Apparently not.

I have had telco people vaguely explain some of the issues and 
abstracts of SS7 signalling involved in calls they were handling for 
"me" to me.

> Phone numbers are an interesting species.  On a global level they 
> are used for call routing.

Yep.

> On a local level however it's not more than a DNS name mapping to 
> some real on-net identifier.

Within a telco?

There's a myriad of ways to do it afaict. The case I know best though 
involved calls inbound to an operator specific prefix (there are a 
set of 4 or so major telco peering exchanges in Ireland, where the 
domestic and transit telcos /must/ be avilable for peering). The 
operator used custom software to map specific numbers to X.25 
"addresses" (I forget the exact X.25 jargon) on their own network to 
deliver the calls to various locations on our network.

> Unfortunatly anyone calling your ported mobile number from outside 
> the mobile networks ends up with the number range holder (you 
> former number range holder)

The operator's prefix, yes.

> who in turn has to forward the call to your current mobile 
> operator.

Yep.

> Outgoing are not affected because the TDM network always sets up 
> parallel in/out path's. The return channel for your outgoing call 
> doesn't come back through your former mobile operator.

I didn't know that, but sounds exactly what you want.

> Now compare this to the Internet and IP routing.  See some little 
> differences and diffculties here and there?  Yea, I thought so.

There are huge differences in the details, obviously. The basic 
concepts though are at least interesting to consider, if not directly 
applicable to IP (technically at least - operationally/politically is 
another question):

1. Providers servicing these prefixes must peer and exchange the
    prefix information

2. Providers must be prepared to carry other providers traffic into
    the area

2a. The providers within the area have to figure out how to bill for
     the difference of this traffic.

> Conclusion: Applying the phone number portability to the Internet 
> is broken by design.

Right, cause phone number portability is up and running for several 
sets of prefixes in various regions across the world[1], so there's 
definitely nothing we can learn from them. ;)

1. Does the US have number portability anywhere? If so, that would be 
a /huge/ region, and very interesting to examine to see how they 
manage it.

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
"Plan to throw one away.  You will anyway."
- Fred Brooks, "The Mythical Man Month"