In this tutorial, we will walk you through the installation of Asterisk on a Debian 9 VPS. Asterisk is the most popular open source software implementation of a telephone private branch exchange (PBX). It includes both classical PBX functionality and many advanced features such as: conference calling, call recorder, voicemail, interactive voice response, automatic call distribution, real time monitoring, debugging console and supports most of the standard voice over IP (VOIP) protocols including SIP, d H.323 and MGCP.
