Voice over IP (also called VoIP, IP Telephony, and Internet telephony) is the 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.
Protocols used to carry voice signals over the IP network are commonly referred to as Voice over IP or VoIP protocols
Voice over IP traffic may be deployed on any IP network, including ones lacking an Internet connection, for instance on a private building-wide LAN.