Linux Networking Cookbook

5.8. Connecting Your Asterisk PBX to Analog Phone Lines

Problem

You're running a small shop with fewer than 10 analog phone lines. You're not quite ready to give up your nice reliable analog phone service, but you do want to set up an Asterisk server for your local PBX, and to integrate some VoIP services. Your first job is connecting Asterisk to your analog lines—how do you do this?

Solution

First, follow the previous recipes to install and test Asterisk's basic functions. In this recipe, we'll route incoming and outgoing calls through Asterisk. Incoming calls will be routed to our existing extension 250, which is probably not how you want to set up your system permanently, but it's fine for testing. Later in this chapter, we'll set up a proper digital receptionist.

Let's assume you have three analog phone lines. You'll need an Asterisk server, and the Digium TDM400P analog interface PCI card with three FXO ports. You'll also need to load the appropriate Zaptel driver, which for this card is the wctdm kernel module.

Install the TDM400P in your Asterisk server. Then, you'll edit /etc/zaptel.conf and /etc/asterisk/zapata.conf. First, make a backup copy of the original /etc/zaptel.conf:

	# mv zaptel.conf zaptel.conf-old

Then, make a new zaptel.conf file with these lines in it. Use your own country code—you'll find a complete list in the zonedata.c file in the Zaptel source tree:

	;zaptel.conf
	loadzone = us
	defaultzone=us
	fxsks=1,2,3

Now, load the wctdm module and verify that it loaded:

	# modprobe ...