SWAN Concentrator Installation and Support Guide

SWAN Concentrator Installation and Support Guide—429391-006
Glossary-1
Glossary
$ZZWAN. See WAN port.
10Base-T. Common name for Ethernet running over twisted-pair cable at 10 Megabits per
second (Mbps).
ADAPTER object. A configurable object within the WAN subsystem SCF interface that
represents a SWAN concentrator.
asynchronous. A mode of data communications transmission in which characters are sent
at random; there is no timing relationship between the end of one character and the
start of the next. Within each character there is a fixed-bit duration that is determined
by the internal clock speeds of both the transmitting and receiving terminals. A
character code defines terminal and line control sequences.
b. Bit (Kbps = Kilobits per second).
B. Byte (KBps = Kilobytes per second).
bit-synchronous. A type of OSI Layer-2 protocol that uses synchronous transmission but
that does not require a character code to define terminal and line control sequences.
An example of a bit-synchronous protocol is X.25.
bits per second (bps). The basic unit of measurement for data communications devices.
Usually refers to rate of information bits transmitted.
byte-synchronous. A type of OSI Layer-2 protocol that uses synchronous transmission
techniques and requires a character code to define terminals and line control
sequences. Data is always transmitted in a block.
CLIP. See communications line interface processor (CLIP).
communications line interface processor (CLIP). The major programmable device within
the SWAN concentrator, providing link-level protocol and a software interface to the
server. The CLIP stores and implements specific communications protocols. There are
three CLIPs on one SWAN concentrator. Each CLIP contains a microprocessor chip.
Each CLIP interfaces to both the A and B Ethernet ports and has two WAN ports.
Compaq TSM. Identifies a client or server software component used to manage or service
HP NonStop S-series servers.
customer replaceable unit (CRU). A component, an assembly, or a subassembly that can
be installed and removed without using special tools, such as a slotted screwdriver or a
utility knife. CRUs create no safety exposures to personnel servicing the CRU. Unlike a
field replaceable unit (FRU), replacement of a CRU does not require any special
personnel training by Tandem. The SWAN concentrator is a CRU.