Don't feel "blonde", unless...well, you actually are. Telephony is very complex.
Not all telephone numbers are portable into all carriers. In the USA, phone numbers are issued to Federally-regulated telephone carriers in large blocks (usually 10,000, but sometimes 1000), by an industry organization known as the North American Numbering Plan Administration (NANPA). A number block is indicated by the first seven digits of the number, like this: 2138675xxx. In this example, it's Area Code 213, prefix 867, and block 5. More than one carrier often has blocks in the same prefix.
When you port a number, you are not actually changing the ownership of that number, which always belongs to the first/original carrier to which that block of numbers was assigned. Instead, the "losing" carrier lets the "gaining" carrier borrow and re-route inbound calls to the gaining carrier's phone switch.
This is all controlled by another neutral, third-party organization, the Number Portability Administration Center (NPAC). If the gaining carrier can host a number from a given block, then it works with NPAC to assign new routing for that number.
When the phone number is in a block that the gaining carrier can't re-route to their switch, it's not portable to that carrier. In your case, apparently no other carrier can host the number.
If you want to use an OBiTALK product, you can get a new phone number from the telephone service provider you wish to use.
