Sometimes it is necessary to determine whether there are enough channels of ground telephone lines, in case if the operator is connected to Asterisk. To collect such statistics in our company, we decided to record every minute (ideally, of course, more often) the number of active calls\channels in Asterisk to file, then plot if required.

There are two steps in the task:

1. Output needed data to file in manual mode.
2. Put the script into cron.