You can stop all the components together or a single component separately.
Use the imadmin command with the stop option to stop the Instant Messaging Server, multiplexor, Calendar agent, cluster agent, and watchdog depending on which components are enabled.
At the command line, type the following:
If the watchdog is running, imadmin brings the watchdog down first, and then stops the server and/or the multiplexor.
This command stops the server, multiplexor, Calendar agent, cluster agent, and watchdog, terminates all end user connections, and disconnects any inbound and outbound servers configured.