A telephone service available both in digital and analogue systems allows displaying a number of the calling subscriber on the display. And where it is
possible the caller’s name can be also lighted up.
Plenty of business companies use free Asterisk software and place it on their server, thus creating a cut-rate IP-PBX. They use manuals provided on setting up the extensions, and occasionally there are lots of discrepancies. Finding out how to install a dial plan or call flow, the set of regulations detailing how the switch deals with inbound and outbound calls is very difficult.