Method 1:
Enter /etc/init.d/sms start to start smsd in background.
Enter /etc/init.d/sms stop to stop smsd.
In case of Unix, you might create links in your runlevel directories (for example /etc/rc3.d or /etc/init.d/rc3.d) if the program shall start and stop automatically together with the operating system.
Method 2:
Run /usr/bin/smsd -s to start the program in a command window.
Press Ctrl-C to stop the program.
Method 3:
Enter /usr/bin/smsd & to start the program in background.
Enter pkill smsd to stop it.
Run the command sendsms 491721234567 'Hello, how are you' to send a message or put an SMS file into the Outgoing Folder /var/spool/sms/outgoing.
To read a received message, take a look into the Incoming Folder /var/spool/sms/incoming.