Overview

This chapter describes in detail how to create a TTGEN configuration file for the ACC X.25 subsystem. It also discusses in detail the implementation and run-time usage of the ACC X.25 subsystem; for example, how to display X.25 specific information using the zmntr utility.

The zx25d X.25 Protocol Driver handles the Level 2 link setup, the Level 3 (virtual circuit) call setup, call clearing, resets, and the exception handling that occurs when errors are detected on an X.25 Virtual Circuit. It does not handle the normal data transfer traffic - this is all processed by the firmware on the mux card. This allows the data handling tasks to be processed efficiently and quickly, while allowing the more complex (but less frequently used) tasks to be managed by this HP-UX driver.

The zx25d driver is initialized by scheduling the program zx25d_init after the ZCOM subsystem has been started by zmon. Normally, these actions are automatically performed when zmasterd is used to start up the ZCOM subsystem. After the ACC X.25 subsystem has been initialized by zx25d_init, this program will normally terminate. A message will be logged to the ZCOM log file indicating the X.25 subsystem is operational.

The remainder of this chapter is intended for those who are using the ZCOM Application Programming Interface (API) to directly access and control the X.25 subsystem. If you are using the X.25/ACC product, you need not read any further.