VoIP is a generic term for using IP data networks like the public Internet to transmit voice traffic, thereby saving long distance and toll costs by bypassing traditional phone companies. IP telephony uses a private IP network - a company's IP data network - for voice calls, delivering the cost and scalability benefits of VoIP while avoiding the unreliability of the Internet.
IP telephony (IPT) offers a viable alternative to the legacy voice exchange, delivering improved application integration, scalability, and multi-site management. It is precisely these features that make this rapidly-maturing technology so attractive to organizations seeking to reduce costs, increase productivity and improve customer relations.