VoIP and ENUM

Last month I posted about the ENUM-enabled number range +43780 that went into operation in Austria. I also posted some FAQs.

Approximately at the same time Telcordia and BearingPoint teamed to deliver ENUM services for the number range +87810 with VoIP providers worldwide via www.87810.com.

Basically +87810 and +43780 work in the same way as decribed in the FAQs. Calls from the PSTN are routed to a gateway which queries ENUM to route the call further on the Internet. Since both solutions use ENUM as defined in RFC3761, the same gateway could be used for both (and also any equivalent) number ranges.

A bit of history:

The number range was allocated by ITU-T in 2001 to VISIONng:
First Mobile Phones, Now Mobile Numbers - ITU allocates code for Universal Personal Telecommunications Number

and delegated by RIPE NCC to Infonova (BearingPoint) on behalf of VISIONng with the approval from ITU-T for trial purposes in May 2002. The trial was operated in parallel with the Austrian ENUM Trial and was first demonstrated at the Fall VON 2002, and again at Spring VON 2003.

The first production service was opened in June 2004 by Sentiro.

I just wonder what happened to VISIONng , the domain name holder, VISIONng is not even mentioned in the press release from telcoria and BearingPoint?

The two number ranges are basically equivalent technically, so what is the difference?

On the Internet there is no difference at all: if you are able to query ENUM in e164.arpa, you will be able to find the destination.

For the user it is a matter of taste if he wants to have a global number or a national number.

The real difference is the behaviour on the PSTN. The number range +43780 is (theoretically) reachable from any country in the world, because the call may by default be routed to Austria and there it will be terminated by the default gateway operated by Telekom Austria.

Why theoretically? Because the routing on the PSTN is a big mess. On the Internet, if a new domain name is created, the web-site is immediatley globally reachable. Not so on the super-reliable PSTN network. The communication between operators on existing number ranges is basically done via e-mail and manually via an ITU-T web-page and it may take years to get a new number range routed globally. It took Liechtenstein two years to get their new country code routed globally.

With +87810 the situation is even worse, because there is no default "country". In countries having also gateways to own ENUM number ranges, the routing is easy, as stated above. In all other countries you need to implement a routing (per operator) to a country which has a gateway. In the US the implementation will be a night-mare.

Just a minor remark to the press release:

There is one statement:

On the other hand, existing (public) ENUM implementations are typically based on national telephone numbers and do not allow the usage of telephone numbers from other national numbering plans.

... which I do not parse.

Of course national numbering plans do not allow the usage of other national numbering plans. You simple cannot get a +43 number from the UK regulator managing +44 numbers, typical or not.