For proprietary conventional PBX you have to call vendor company. They send an engineer and add/modify features in PBX.

Our VoIP service works on Smart Phone or any Wifi IP Phone. All you need is just an internet connection. It could be your GPRS or Wifi connection.

VoIP is an abbreviation for Voice over IP, or in plain words It is a telephone running over Internet, it could be running on home router, GPRS, Wi-fi or WiMax.