It is a device capturing and controling all the signals, which are being created by the whole system, especially the made and received phone call signals. The device is mostly used for connecting regular phone system with the Internet and backwards.
Konftel 300IP - connects to VoIP-lines via SIP protocol. This phone is equipped with advanced features that allow making more efficient conference calls. For example, you can record and store records of meetings using the memory of SD card.