VOIP virtual numbers

Question

I recently purchased a virtual number which is similiar to local landline number provided by my local provider.

how voip provider can provide virtual numbers over VOIP?

Do they have contract with telecommunication company or make their own numbers?

Is Asterik able to integrate local numbers?

I asked the same question for VOIP provider but they are unable to provide me answer. How can these companies provide virtual numbers from around the world?

Answer 1

Do they have contract with telecommunication company or make their own numbers?

Each country has it's own top level "regulator" that is responsible for telephone number management.

A VoIP provider needs to have a contract with that regulator which gives them a block (or multiple blocks) of telephone numbers they can then assign to their customers.

For example:

In Germany it is the Bun­desnet­za­gen­tur

is responsible for structuring the national numbering space, setting the conditions for allocating and using numbers, and processing applications for numbers and number blocks.

In the UK it is Ofcom

This section provides information about UK Telephone Numbers, and allows Communications Providers to apply for Telephone Numbers from the National Numbering Scheme.

In the UK you have to be a communications provider to apply for a number or block of numbers.

As a consumer you are allocated a number by the provider you sign up with.

Answer 2

Nowdays most "usual" providers use sip, isdn, h323 or other DIGITAL communication protocol to deliver call.

So it is posible get same numbers in digital form via SIP for example(using gate at provider or isdn2sip at organization which do re-sell).

After that your VOIP provider can have multiple contracts with such re-seller(or direct contracts to providers like British Telecom) and sell you thoose number at 2x cost.