APN Event Management Programming Manual

Glossary

SNAX/XF and SNAX/APN Event Management Programming Manual—426859-001

Glossary-18

Subsystem Control Facility (SCF)

Subsystem Control Facility (SCF). A Compaq product that is used to interactively

configure, control, and collect information about Compaq data communications

subsystems. SCF can be used to dynamically configure and manage the entities in the

SNAX/XF environment.

Subsystem Control Point (SCP). The management process for many Compaq subsystems.

Several instances of this process can run on a system. Applications using SPI, including

SCF, send all commands for subsystems that support SCP to an instance of this process,

which in turn sends the commands on to the manager processes of the target subsystems.

SCP also processes a few commands itself. It provides security features, version

compatibility, support for tracing, and support for applications implemented as process

pairs.

subsystem ID (ZSPI-TKN-SSID). In management applications, a data structure that

uniquely identifies a subsystem to SPI. The subsystem ID is specified in SPI commands

to identify the target subsystem and, in EMS event messages, to identify the source of

the event message. The subsystem ID is an argument to most SPI procedures.

Subsystem Programmatic Interface (SPI). Part of the DSM family of software products. A

standard set of procedures and associated definition files used to define common

message-based programmatic interfaces for communication between requesters and

servers—for instance, in a management application. SPI includes procedures to build

and decode specially formatted messages; definition files in Pascal, TAL, C, COBOL85,

and TACL for inclusion in programs, macros, and routines using the SPI procedures;

and definition files in DDL for programmers writing their own subsystems.

SVC. Switched virtual circuit.

switched connection. A temporary association established between two PUs when a PU

accepts a call-in. This connection can be initiated in many different ways, such as a

telephone dial operation or a call-out request packet on a packet switched network.

switched floating LU. In SNAX/XF, an LU that is subordinate to a switched floating PU.

When a switched floating PU becomes subordinate to a line, all switched floating LUs

subordinate to that switched floating PU also become subordinate to the line.

switched floating PU. In SNAX/XF, a PU that is not permanently subordinate to any line,

but rather is temporarily subordinate to the service manager (the SUBSYS object) until

it becomes temporarily subordinate to a switched line because it is needed.

switched line. A telecommunications line in which the connection is established by dialing.