ACC X.25 Protocol User's Guide

ZX25D X.25 Protocol Driver
Overview
Chapter 328
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.