Chances are, if you've use a service like Vonage, voip.com, or Skype, you've seen that they provide local telephone numbers nationwide. Ever wonder how they do that?

It boils down to two choices: become a competitive local exchange carrier (CLEC) or partner with one. Most companies choose the latter route. Level 3, XO, and other CLECs, along with other number wholesalers like Voxbone and DIDX provide numbers worldwide inbound telephone numbers to service providers.