OSI/TS Management Programming Manual

1 Introduction
056786 Tandem Computers Incorporated 1–1
The Tandem OSI/TS (Open Systems Interconnection/Transport Services) subsystem
provides a Transport Layer interface to OSI networks. OSI/TS requires one of the
following Tandem access methods to provide the services of layers below the
Transport Layer:
X.25 Access Method, X25AM (for wide area networks)
Tandem LAN Access Method, TLAM (for local area networks)
OSI/TS supports Tandem’s Distributed Systems Management (DSM) facilities for
subsystem management. DSM provides a management interface to subsystems,
through commands that perform operations on subsystem objects and event messages
that report significant events detected by the subsystem.
Commands provide a two-way interface: a human operator or a management
application sends a command to a subsystem, and the subsystem then performs some
action and returns a response to the operator or application. Event messages, on the
other hand, provide a one-way interface: information flows from the subsystem to the
operator or management application, but no information flows in the other direction.
For commands and event messages, OSI/TS supports both interactive and
programmatic interfaces.
The Subsystem Control Facility (SCF) is an interactive interface that allows a human
operator to send DSM commands to Tandem data communications subsystems,
including OSI/TS. The Event Management Service (EMS) includes printing and
compatibility distributor processes that can print or display event messages for
operators. The ViewPoint console application includes screens that allow selective
viewing of event messages.
The DSM programmatic interfaces for sending commands (control and inquiry) and
retrieving event messages (event management) allow programs to perform the same
kind of monitoring and control operations that users of SCF, EMS printing and
compatibility distributors, and ViewPoint can perform interactively.
Why Management
Programming for
OSI/TS?
In some situations, it is desirable to use a programmatic interface, rather than an
interactive interface, to manage a subsystem such as OSI/TS. This is true for the
following reasons:
It is efficient to transfer as many routine network-management tasks as possible to
programs, freeing people to do the work that requires judgment and creativity.
Information obtained through programmatic interfaces can be translated directly
into procedures, reports, and so forth.
An application that uses programmatic interfaces to subsystems can perform tasks that
once required several different interactive interfaces. In addition, the capability to
write your own management applications allows you to tailor them to the needs and
configuration of your network.