SNAX Connection Manager (SNAX/CM) Manual

Glossary
097842 Tandem Computers Incorporated Glossary–3
event. A significant change in some condition in the system or network. Events can be
operational errors, notifications of limits exceeded, requests for action, notifications of
lines and other objects becoming available, and so on. Note that an event is not always
an error.
event message. An SPI message that describes an event occurring in the system or
network. Compare command message or response message.
Exchange Identification (XID). A value that identifies which PUs connect to a SNAX/XF
line.
Expand network. A network consisting of Tandem systems interconnected by
communication links and supported by Expand software.
fault-tolerant. An attribute of the Tandem NonStop system whereby a processor failure
does not result in loss of data or function.
floating LU. See switched floating LU.
floating PU. See switched floating PU.
frame. The unit of transmission in a Token-Ring network. It includes delimiters,
control characters, data, and checking characters. There are two types of frame, data
and MAC. A data frame is used to transport application-level data between stations
on the ring. A MAC frame contains no application data; it is used to transport control
and network management information between adapters attached to the ring.
gateway LU. An LU subordinate to a gateway line on a gateway system. SNAX/XF
transparently handles the passing of information between gateway LUs and the
processes and devices residing on a Tandem system.
gateway PU. A PU subordinate to a gateway line on a gateway system.
gateway system. A Tandem system that has a SNAX communications link to an SNA
host.
gateway. A special node that interfaces two or more dissimilar networks, providing
protocol translation between the networks.
group address. A single address assigned to a group of service access points.
hexadecimal. A numerical value in base 16; digits go from 0 to F. Tandem prefaces
hexadecimal notation with %H.
host. A general purpose processor, such as an IBM 3033, that contains an SSCP, PU
type 5 logic, and one or more LUs representing different applications or application
subsystems.
I/O process. A system process that manages I/O hardware, such as in a Token-Ring or
X.25 network configuration. Applications use the file system to send requests to I/O
processes.
IEEE 802. Standards for the interconnection of LAN computer equipment.