The asterisk character (*
) is
used as a wildcard in many different applications. It is a good name for this
PBX for many reasons, one of which is the enormous number of interface
types to which Asterisk can connect. These include:
Analog interfaces, such as your telephone line and analog telephones
VoIP protocols such as SIP and IAX[51]
Asterisk doesn’t need any specialized hardware—not even a sound card—even though it is common to expect a telephone system to physically connect to a voice network. There are many types of channel cards that allow you to connect your Asterisk to things like analog phones or PSTN circuits, but they are not essential to the functioning of Asterisk. On the user (or station) side of the system, you can choose from all kinds of softphones that are available for Windows, Linux, and other operating systems—or use almost any physical IP phone. That handles the telephone side of the system. On the carrier side, if you don’t connect directly to a circuit from your central office, you can still route your calls over the Internet using a VoIP service provider.