SNAX/XF LU Network Services Manual

Glossary
097841 Tandem Computers Incorporated Glossary–5
NonStop operation. A Tandem system behavior characterized by continued operation
even when a component fails, when equipment is being repaired or replaced, or while
new processors or peripheral devices are being added to the system. Legally used
only to describe the Tandem NonStop system or its features, such as NonStop process
pairs.
NS. Network services (one of the SNA functional layers).
NSH. Network services header.
OBEY file. A file that serves as a source for command input.
object. In Tandem terminology, an object is an entity that can be configured,
controlled, and inquired about by the operator.
passthrough. A function of the SNAX/XF line access software that allows a 3270
terminal attached to a Tandem system to switch between Tandem and IBM
applications. Passthrough lets a host application program communicate with SNA
devices connected to a Tandem system as though the devices were connected to a
cluster controller.
Passthrough is enabled by configuration and startup procedures; it is never directly
invoked by application software. Passthrough can also be used to perform service or
management tasks that are incidental to SNA applications on a Tandem system.
Passthrough sessions. An SNA session used in Passthrough.
Pathway. A transaction processing system that supplies the programs, procedures, and
structures necessary to produce user-written applications. The CRT protocol is used
by Pathway.
PC. Path control.
PDN. Public Data Network.
peripheral node. A node consisting of a physical unit type 1 (node type 1) or a physical
unit type 2 (node type 2) device that is directly connected and under the control of an
adjacent subarea node. Routing to a peripheral node occurs through the local address
only and is not affected by the network addressing scheme. Boundary function
assistance is provided by the adjacent subarea node.
physical connection. The media (hardware and software) through which data is passed
between origin and destination subareas. Physical connections between a host
processor and a communication controller in an SNA network can be made by either
an SDLC link or a channel attachment.
physical unit (PU). That part of a device (hardware or software) that provides control
functions for its own node and for the other less intelligent device nodes attached to
the PU. Every device or logical unit in an SNA network is associated with a physical
unit.
PID. Process identifier.
PLU. Primary logical unit.