PBX in a Flash for Newbies

Creating a POTS line trunk to a PSTN

FXO ports are used to connect to a POTS trunk from the PSTN. In simple terms, if you want to connect an Asterisk PBX to your local phone line, you will need an FXO port. On the TDM400P cards that we use, channel 4 is our FXO port.

There are three steps to making an FXO port work:

1. Adding a FXO Trunk

   This identifies the hardware trunk to Asterisk

2. Configuring a Simple Inbound Route

   This sets the rules for incoming calls on the FXO port

3. Configuring a Dial 9 Outbound Route

   This sets the rules for placing an outgoing call to the FXO port