In an issabel this would be the command.
Access with the asterisk user:
crontab -eu asterisk
You create the cron to your measure
* / usr / sbin / asterisk -rx 'sip reload'
Then you restart the service and ready!
service crond restart
(
@yearly : Run once a year, ie. 0 0 1 1
@annually : Run once a year, ie. 0 0 1 1
@monthly : Run once a month, ie. 0 0 1
@weekly : Run once a week, ie. 0 0 0
@daily : Run once a day, ie. 0 0
@hourly : Run once an hour, ie. 0 *
)