Expand Management Programming Manual
 SECTION 2
 MANAGEMENT PROGRAMMING FOR THE EXPAND SUBSYSTEM
 As seen in the previous section, there are several different
 interfaces, both interactive and programmatic, to the EXPAND
 subsystem. In some situations, the programmatic interfaces would
 be preferred over the interactive interfaces for the following
 reasons:
 • It is efficient to transfer as many routine network-management
 tasks as possible to programs running on the computer network
 itself, freeing operators and other network-management person-
 nel to do the work that requires judgment and creativity.
 • Information obtained through the programmatic interfaces can
 be used directly by an application to control its actions,
 produce reports, and so forth.
 An application that uses the control-and-inquiry and event-
 management interfaces can perform tasks that once required
 the use of two or three interactive interfaces, and such an
 application can also communicate with multiple subsystems. In
 addition, the capability to write your own applications allows
 you to tailor them to the needs and configuration of your
 network.
 You could, for example, write an application that uses the
 control-and-inquiry interface to check the number of errors
 occurring on all the EXPAND lines in the network and stop
 lines that have too many errors. An application could monitor
 the events occurring in the EXPAND subsystem and react to the
 notification that a line is going down by starting another line
 to handle the traffic.
 Your applications can communicate with other subsystems as well
 as with the EXPAND subsystem. For example, you could write an
 application that uses the EXPAND subsystem to bring up an EXPAND
 line to a remote system and then uses the PATHWAY subsystem to
 2-1










