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.
Conferencing is related to the service, which allows creating the
conference when all participants are in different places. It gives a chance to
communicate, exchange data and correspond in real time and also allows using
the video signal that gives a chance to see one another.