The term used for LAN-attached telephony systems and the associated telephone handsets (that is, the IP version of the PBX). More specifically, IP telephony involves the delivery of the telephony appl [..]

Telephony functionality provided over a data network.

Transmitting and receiving telephone messages via the Internet. Messages are broken into packets and exchanged using the Internet protocols.

IP Telephony refers to voice telephone service provided over an IP network instead of the public-switched telephone service.