Introduction to Tandem X.25 Capabilities

X25AM Connectivity
Tandem X.25 Features and Capabilities
2–20 065307 Tandem Computers Incorporated
Connecting Multiple
Tandem Systems
Tandem systems are usually connected to each other by using the Expand product.
Tandem systems at remote locations can communicate with each other via a PSDN by
using the Expand process over an X25AM line. Like other X.25 connections, the cost of
data communications may be less than it is for dedicated lines when line use is
intermittent. The Expand subsystem’s implementation of X.25 also has additional
cost-saving benefits: connections can be disconnected when not in use and then
automatically reconnected when traffic appears. Also, the Expand multiline path
feature further enhances the inherent reliability of X.25 connections. This feature can
be used to configure an Expand process to manage up to eight lines, including X.25
connections, between neighbor systems.
For this type of connectivity, you define the X25AM subdevice for the NAM protocol.
(Some earlier versions of X25AM referred to this protocol as NET. NAM is the current
term.) For detailed line configuration information, refer to the System Generation
Manual for Expand. You do not need to write a communications application to use the
NAM protocol.