Switching to VoIP

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Asterisk Dial-Plan

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Included configuration files are expected to have a structure that is also valid for the

file they are included into.

Asterisk Dial-Plan

All calls placed to, from, and through the Asterisk PBX are handled on logical voice

pathways. A pathway may consist of a single hard line, like an analog telephone line

interfaced with Asterisk via an X100P card, or there may be hundreds of pathways

sharing a single physical connection, like a bunch of SIP phones connected to the

Asterisk server via an Ethernet interface. In any scenario, the pathways are called

channels, and the Asterisk PBX’s purpose is to handle their voice traffic according to

a set of rules known as a dial-plan. The effect the dial-plan has on a call is called a

call flow.

Many conventional PBX systems use dial-plans to deal only with calls that can be

placed and answered when a human is present and require an offboard voice mail

server with an auto-attendant to answer calls when nobody’s in the office. But the

Asterisk PBX uses dial-plan for a much larger purpose: complete call processing for

both scenarios. The Asterisk dial-plan includes rules that specify what to do when:

• A call comes in on a particular channel or from a certain caller—i.e., if the call is

from this line, handle it a certain way.

•