The TN3270E Telnet server application uses UNIX System Services; when OMVS is shut down, Telnet services are no longer available. To prevent Telnet from abnormally ending, Telnet is automatically stopped prior to OMVS shutdown, and can be restarted after OMVS is restarted.
Telnet automatically registers with OMVS; because of this registration, OMVS notifies Telnet when OMVS shutdown is requested, and OMVS waits for Telnet to stop. When Telnet is notified of the OMVS shutdown, it immediately begins to stop, as if the MVS™ STOP command had been issued. After Telnet is stopped, OMVS shutdown is no longer blocked by the Telnet server.
If you plan to shut down OMVS, be sure your Telnet users are logged off before you shut down OMVS.