Over 90 service providers have registered more than 300 million phone numbers with the ENUM-like Spider registry set up by Arbinet a year ago. That is probably more than the number of Skype downloads so far! Before we think of apples-to-apples comparison, let us go slightly deeper into what this Spider thing is.
Spider is a registry for sharing telephone numbers. Arbinet along with NetNumber set up the initiative. Basically Arbinet, which is a leading voice minutes exchange company, got the members of its exchange to agree to share their phone numbers into the registry so that Arbinet could route calls direct to them. When a call hits the Arbinet system, its server (an internally developed SCP solution) queries Spider to see whether that unique phone number is ‘on-net’ to Arbinet i.e. whether the phone number is owned by one of the connected members (and whether the connected member carrier has registered that phone number in the Spider registry). If the answer is positive, Arbinet system routes the call direct to the service provider. No IXCs and no LD carriers in the middle.
So where do these 300 million numbers come from? Arbinet has been aggressive in getting South American service providers to sign up. In Argentina alone there are two large carriers - Telecom Argentina and Telefonica Argentina - that handle about 40% of the market each that have registered their phone numbers in the Spider registry.
Spider has numbers almost in every country in South America.
The registry is comprised of PSTN numbers mostly. Arbinet has not yet disclosed the number of VoIP endpoints in the registry. But it must be a small proportion. Most other peering providers have VoIP numbers only in their registries. There are about 55.4 million VoIP end points worldwide. At some point most of the Spider registered numbers will become VoIP numbers but carriers between themselves do not need to know about the change.
In terms of the type of service providers that connect to Spider registry, these are mostly the existing exchange members. That includes some of the cable companies as well as mobile companies. Spider registry is a global non-profit entity. It works in registry-registrar kind of structure. Arbinet is one of the registrars. VoEX is another registrar. Any company that brings in its own registry can be a registrar.
The registry is not an ENUM server. But it was designed as an ENUM-like or DNS-type query system where the SCP of Arbinet is set up to query the registry. Spider uses technology from NetNumber. NetNumber develops high end addressing servers that carry out queries such as ENUM, DNS, INAP, and SIP Redirect.
Anyway, the 300 million figure sounds quite large. I have a feeling that there are certain prefixes registered in there i.e. prefixes that imply a whole set of numbers with specified termination costs associated with those prefixes. If that is the case, then not only are the numbers beefed up, but the registry could partly be in use as LCR routing system.