Page 108 - Asterisk™: The Future of Telephony

Zaptel Configuration
======================
Channel map:

Channel 01: FXO Kewlstart (Default) (Slaves: 01)
Channel 02: FXS Kewlstart (Default) (Slaves: 02)
2 channels configured.

Zapata Hardware Configuration

The following configuration is identical to that for the FXO channel, with the addition
of a section for our FXS port and, of the line immediate=no. The context for our FXS
port is phones, the signaling is fxoks (kewlstart), and the channel number is set to 1.
FXS channels can be configured to perform one of two different actions when a phone
is taken off the hook. The most common (and often expected) option is for Asterisk to
produce a dial tone and wait for input from the user. This action is configured with
immediate=no. The alternative action is for Asterisk to automatically perform a set of
instructions configured in the dialplan instead of producing a dial tone, which you
†
indicate by configuring immediate=yes. The instructions to be performed are found in
the context configured for the channel and will match the s extension (both of these
topics will be discussed further in the following chapter).
Here’s our new zapata.conf:
[trunkgroups]
; define any trunk groups
[channels]
; hardware channels
; default
usecallerid=yes
hidecallerid=no
callwaiting=no
threewaycalling=yes
transfer=yes
echocancel=yes
echotraining=yes
immediate=no
; define channels
context=phones ; Uses the [internal] context in extensions.conf
signalling=fxo_ks ; Uses FXO signalling for an FXS channel

channel => 1 ; Telephone attached to port 1

† Also referred to as the Batphone method, and more formally known as an Automatic Ringdown or Private
Line Automatic Ringdown (PLAR) circuit. This method is commonly used at rental car counters and airports.

80 | Chapter 4: Initial Configuration of Asterisk