SIP Client integrates Barix devices into an existing VOIP phone system. It works with most SIP based VoIP solutions including Cisco Unified Communications Manager or Asterisk. Using the Session Initiation Protocol (SIP), the client device receives a phone number in addition to its IP address and can communicate either on a peer-to-peer connection or over a proxy-based connection (PBX). Ringtone and busy tone guarantees that the call remains confidential and the recipient really receives the information. Featuring background music, audio rebroadcasting and special DTMF commands to quickly manage the device, the SIP Client is easy to integrate into an existing telephone system. Four different relay ports can be configured to open doors, windows, or to activate machines while simultaneously speaking.