SNAX Connection Manager (SNAX/CM) Manual

Glossary
Glossary–4 097842 Tandem Computers Incorporated
leased line. A connection between systems or devices that does not have to be made by
dialing, synonymous with nonswitched line. A telephone line reserved for exclusive
(private) use of the leasing customer.
link. The logical connection between nodes, including the end-to-end link control
procedures.
link station. A protocol machine in an SNA node that manages the exchange of
information between a link station in another node and the upper SNA layers in its
own node.
logical unit (LU). In SNA, a port through which an end user accesses the SNA network
to communicate with another end user. An LU establishes the connections for the
transmission of data between end users in the network. LUs are associated with either
application programs or a device.
LU. See logical unit.
MAC address. The address that originates or receives data on a Token-Ring network.See
destination address and source address. See also medium access control (MAC).
medium . A physical carrier of electricity.
medium access control (MAC) . The sub-layer of DLC that supports medium-dependent
functions and uses the services of the physical layer to provide services to the LLC.
network. A group of interconnected computer systems and devices, and the hardware
and software used to connect them.
network address. In SNA, an address, consisting of subarea and element fields, that
identifies a network addressable unit. Subarea nodes use network addresses;
peripheral nodes use local addresses. The boundary function in the subarea node to
which a peripheral node is attached transforms local addresses to network addresses
and vice versa.
node. In SNA, an endpoint of a link or junction common to two or more links in a
network. There are peripheral and subarea nodes. Nodes include host processors,
communication controllers, cluster controllers, or terminals, and vary in routing and
other functional capabilities. Each SNA node must contain at least one NAU.
node ID verification. A SNAX/XF switched-line feature that allows the Tandem system
to perform node ID verification by means of the SDLC XID commands and responses.
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.
nonswitched line. (1) A communications link that is permanently installed between two
points, also called a leased line or private line. (2) A connection between a remote
station and a communications controller that does not have to be established by
dialing. Synonymous with leased line. See also switched line.