Hello Ali:
Everything depends on the capacity you want to use, the price, and how familiar are you with computers or routers. Definitively, if you’re a “normal” computer user, you can do everything easily with CPM (including pre-paid calling cards business).
If you’re more experienced with routers, you can use other solutions like Cisco or Quintum. It’s not too much easy nor unexpensive to use these equipments for pre-paid calling cards business.