Call waiting with “Caller ID” uses a special signal in
order to warn you about an incoming call, during another call there are shown the
name and number of the calling subscriber on the display. The function also
allows switching between two calls.
It is is considered as one of the most prominent entity in the VoIP world. Company Digium has created it as a fully innovative approach to telecommunications. This company has delivered such software that enables people to configure a server and start to make calls.