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.
Main portion of the advantages of the Asterisk server appears from it being an open source downloadable product. Most of the users, especially business people, can find it difficult to understand the idea behind this principle, or free software, but a business models behind open source are different and specific, as in case with Asterisk server.