OSI/TS Configuration and Management Manual

Configuring the OSI/TS Subsystem
OSI/TS Configuration and Management Manual—424831-001
3-33
Single TSP Process Supporting Multiple X25AM
Lines
Limitations
This type of configuration has the following limitations:
Command File for a Single TSP Process Supporting Multiple
X25AM Lines
In this next example command file, a single TSP process supports four X25AM lines.
Each line is configured for three subdevices. (In reality, the number of TSP subdevices
for each line would be much larger.)
The source code file for this example is provided as part of the OSI/TS software. It
resides (by default) in the volume and subvolume $SYSTEM.ZOSITS. The source code
for this example is provided in the file EXCFG6, as follows:
=============================================================
== File: EXCFG6
==
== Example command file for configuring and starting
== processes and subdevices for large applications in which
== a single TSP process supports multiple X.25 lines
== (X25AM). Each line is configured for three
== subdevices. SCF must be running before you use the
== OBEY command to invoke this file.
==
== NOTE: To use this command file for your subsystem, you
== must supply names and addresses that reflect your
== environment.
=============================================================
==
allow all errors
==
== Abort any processes and subdevices that are running and
== that have the same name as you are configuring.
==
Fault tolerance A single TSP process can also be the single point of failure. Any
problem with this one process, or with the CPU in which it runs,
affects the whole application. Although NonStop processing
requires two separate processes in two separate CPUs, when the
backup CPU and backup process take over the connections are
lost and an interruption of the communication occurs.
Load distribution There is no way to balance the load in the Transport Layer. The
single TSP process may become a bottleneck for the application.
Resources A single TSP has limited resources. The buffer pool space of one
TSP process is limited to about 2 megabytes. This may not be
sufficient to support a large number of requesters. In addition,
the maximum number of connections is a limiting factor when
using a single TSP process.
Startup time The startup time may be longer if a large number of subdevices
need to be added before any connection is established.