Voice-over-Internet-Protocol (VoIP) allows users to make phone calls using the internet rather than traditional phone systems. While Thai companies are just now adopting VoIP in large numbers, hosted VoIP solutions provide many advantages over traditional phone systems, including lower call rates, free internal calls, scalability, mobility, and clear call quality without requiring expensive on-premise equipment. The document describes features of a hosted VoIP solution such as CallControl that provide call management capabilities and integration with other business applications.