The program is used for conversation in a local network. The voice packages are transmitted in a format GSM6.10. Voice packages and service information use one and the same UDP port: 4444. The program works without Server. The ContactList traces if the client is online or offline in a network. Mixer allows to control sensitivity of a microphone and loudness of speaker. Simultaneous work with 5 clients. The sound card should be duplex. The program is distributed with the source code.