TDM400
From KlavoWiki
The TDM400/TDM410 is a 4 port analogue card that can have a mixture of FXO and FXS modules totalling no more than 4.
The following configuration is to configure the card with a single FXS module in slot number 4.
/etc/zaptel.conf
fxsks=4
/etc/asterisk/zapata.conf
signalling=fxs_ks channel => 4
NOTE:The order of the lines above is important. The signalling must come before group and group must come before channel.
If your Digium card has an echo cancellation board install also add the following line to enable echo cancellation.
/etc/asterisk/zapata.conf
echocancel=yes