Asterisk Voice Exchange: An Alternative to Conventional EPBX

This paper highlights the design and implementation aspects of a VoIP based asterisk voice exchange, developing a fully functional voice exchange requires to set up a server based on Asterisk, connecting clients to that server with the help of soft phones and then configuring the soft phones with the server. Here in our implementation we have connected the clients to the server with the help of IAX protocols. The first part of the paper contains some introductory concepts about VoIP, followed by asterisk's internal architecture. In the third part of the paper we discuss about the codecs and protocols used by the packet switching based PBX networks and finally we brush up about the design and implementation aspects.