The LIPZ4 is a soft phone that runs on the Linux operating system. By using SIP for the call control, the LIPZ4 is compatible with other soft phones, IP phones, and IP phone systems or networks. When used with a speaker or headset and a microphone on your PC, the LIPZ4 is a cost efficient and convenient way to provide telephone communication. Use it within the enterprise to turn Linux desktops into telephones. Use it over the Internet to save money on long distance calls. The LIPZ4 can communicate point to point with another SIP endpoint or with a SIP application server or gateway.