Digium TDM410 - Driver Configuration

Digium, Inc. Page 38
Chapter 3: Configuration
Driver Configuration
1. Begin by opening the system.conf file from the
/etc/dahdi directory.
2. Specify the two letter country code for your loadzone and defaultzone.
This will preload tone zone data and specify a default tone zone for
your interfaces.
The following is a typical setup for a telco in the US:
loadzone = us
defaultzone = us
http://ArtTel.ru