User guide

Channel 01: FXS Loopstart (Default) (Slaves: 01)
1 channels configured.
Step 4: Configuring Asterisk to use the Zapata Hardware
The forth and final step is to configure Asterisk to use the hardware. This is done in the
/etc/asterisk/zapata.conf file:
[channels]
usecallerid=yes
hidecallerid=no
callwaiting=no
threewaycalling=yes
transfer=yes
echocancel=yes
echotraining=yes
context=incoming_pstn
signalling=fxs_ls
channel => 1
The last three lines of the configuration file are the most important for a default configuration. The line
context=incoming_pstn indicates that all incoming calls are associated with that context. The next two
lines set the signalling (fxs_ls) for this zapata channel (channel => 1).
Once we have configured this new type of channel (zapata channel), we are almost ready to receive
and place phone calls to and from the PSTN.
8.1.1 Handling PSTN incoming calls
The desirable behaviour for incoming PSTN calls is the following: once an incoming phone call arrives
by the analogue telephone line, we want an interactive voice response (IVR) system to ask the caller for
an extension. As we have several internal VoIP clients in our internal telephony network, we want to
make them available to anyone who calls to the PBX's analogue line. This intelligence is implemented
in the extensions.conf file by adding a section [incoming_pstn] as follows:
[incoming_pstn]
Page 36 TRICALCAR | www.wilac.net/tricalcar – Version: February 2008