Com parameters are used to define communication services. The Teradata QS communications components also use these parameters to provide communication services to the Teradata QS servers. Some of the Com parameters are read-only during the start up phase of the corresponding component.
Typically, none of the Com parameters should need to be changed. However, depending on which configuration parameters are changed, there may be a need to shut down and restart the Teradata Query Scheduler Operations tool and all the Teradata QS software for your changes to take affect.
See Changing General Communication Information and Changing Default Server Information to learn how to change Com parameters.