IP Telephony (also called Voice over IP, IP Telephony, and Internet Telephony) refers to technology that enables routing of voice conversations over the Internet or any other IP network. The voice data flows over a general-purpose packet-switched network, instead of the traditional dedicated, circuit-switched voice transmission lines.
IP Telephony has the capability to carry normal telephony-style voice over an IP-based internet with POTS-like functionality, reliability, and voice quality. IP Telephony enables a router to carry voice traffic over an IP network.
In IP Telephony, the Digital Signaling Processor (DSP) segments the voice signal into frames, which then are coupled in groups of two and stored in voice packets. These voice packets are transported using IP in compliance with ITU-T specification.
Key benefits of IP Telephony
Cost savings, single infrastructure savings, and new applications
Packet telephony call center versus a circuit-switched call center
Service provider prepaid calling card application
Service provider enhanced services such as Internet call waiting and click to call
