On 25 Jan 2008, at 10:42, Roland Perry wrote:
writes Tunnels all over the place seems like the only way it'd even be halfway practical. It's more-or-less how phone number portability works anyway, from what (little) I know. I don't know about the USA, but in the UK it's done with something similar to DNS. The telephone system looks up the first N digits of
In article <20080125093035.GH17698@hezmatt.org>, Matt Palmer <mpalmer@hezmatt.org the number to determine the operator it was first issued to. And places a query to them. That either causes the call to be accepted and routed, or they get an answer back saying "sorry, that number has been ported to operator FOO-TEL, go ask them instead".
Not quite, the simplistic overview is that operators have an obligation to offer porting wherever practical, so operate ports on a accept-then-forward principal. If I port my number from CarrierA to CarrierB, then my calls still pass through A's switch, who transits the call to B without charging the end user. For the benefit of completeness, the regulator has mandated that this situation must change, as CarrierB's inward-port customers are not protected from the technical or commercial failure of CarrierA. The industry [www.ukporting.com] has responded and is building a framework to support all-call-query style lookups to handle number ports. Best wishes, Andy