I screwed the DAHDI board somehow and noticed the following error when I dialed the call from the analog line:
WARNING[7238]: pbx.c:12314 ast_context_verify_includes: Context ‘local’ tries to include nonexistent context ‘parkedcalls’
The error occurred because the res_parking module was not loaded to load it, open the asterisk console and execute the command:
sudo asterisk -vvr module load res_parking
To automatically load it when starting Asterisk, in the file /etc/asterisk/modules.conf, in the [modules] block, add the line:
load => res_parking.so