IP telephony (Internet Protocol Telephony) is a general term for the technologies that use the Internet Protocol’s packet-switched connections to exchange voice, fax, and other forms of information that have traditionally been carried over the dedicated circuit-switched Network. IP telephony transmits voice communications over the network using open, standards-based Internet Protocol.
As such, it provides a way for you to extend consistent voice communications services to all your employees in their workspaces – on the main campus, at branch offices, remote, or mobile. Cisco IP telephony solutions are an integral part of Cisco Unified Communications, which unify voice, video, data, and mobile applications on fixed and mobile networks.
They let your employees talk with each other using almost any media, device, or operating system.