NonStop S-Series System Expansion and Reduction Guide

Glossary
G-Series Common Glossary
Glossary-112
Token-Ring ServerNet adapter (TRSA)
Services (OSS) environments. TNS/R native SRLs can be either public or private. A
TNS/R native process can have multiple public SRLs but only one private SRL.
Token-Ring ServerNet adapter (TRSA). A ServerNet adapter that provides a single line
from an HP NonStop™ S-series server to a token-ring network, allowing the server to
act as a station on the ring. The 3862 TRSA can be configured to support network
speeds of 4 megabits/second (Mbps) or 16 Mbps, and the media can be either
shielded twisted pair (STP)
or unshielded twisted pair (UTP).
topology. The physical layout of components that define a local area network (LAN), wide
area network (WAN), or ServerNet fabric. See also star topology
and tetrahedral
topology.
topology branch. A processor enclosure and the I/O enclosures attached to it.
total harmonic distortion (THD). The ratio, expressed in percent, of the root mean square
(rms) value for all harmonics present in the output of a power source to the total rms
voltage at the output, for a pure sine-wave output. The lower the THD, the better the
power source.
Total Information Manager (TIM). See HP NonStop™ Technical Library (NTL).
transformer. Equipment used to step up or step down alternating-current (AC) voltage to
meet the specific requirements of the load. A transformer also provides isolation and
noise-attenuation properties.
transient. A short-duration, high-amplitude impulse that is imposed on the normal voltage or
current.
translation lookaside buffer (TLB). A special-purpose cache, part of the RISC processor
chip, that is used in quickly translating virtual addresses to physical addresses. This
rapid translation is accomplished by remembering and reusing the translations of
recently referenced pages.
Transmission Control Protocol (TCP). A connection-oriented protocol that provides for the
reliable exchange of data between a sending and a receiving system. TCP implements
functions corresponding to the Open Systems Interconnection (OSI) reference model
Layer 4, the transport layer.
Transmission Control Protocol/Internet Protocol (TCP/IP). A set of layered
communication protocols for connecting workstations and larger systems in both local
area networks (LANs) and wide area networks (WANs). See also HP NonStop™
TCP/IP and Parallel Library TCP/IP.
tri-star topology. A network topology that uses up to three HP NonStop™ Cluster Switches
for each external fabric. External routing is implemented between the three star groups
of a ServerNet cluster. (A star group consists of the eight nodes attached to one set of
cluster switches.) The star groups are joined by two-lane link
s. Introduced with the