Verilink AS2000: The Basics (880-502981-001) Product Manual User Manual
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Acronyms and Definitions
Verilink Access System 2000: Basics
Glossary-39
PROM
Programmable Read-Only Memory.
protocol
The set of rules governing the
format, timing, sequencing, and
error control of exchanged
messages over a network or
between devices. Needed for data
transfer and communication
between two directly connected
organized units.
PSES
P-bit Severely Errored Seconds. A
second during which a DS3 circuit
experiences 44 or more PCVs OR
one or more Out of Frame defects
OR a detected incoming AIS. The
PSES count does not increase when
UASs are counted.
public switched telephone network
(PSTN)
The public network operated by
carriers who provide leased lines
and packet-switched circuits so
users can connect customer site
equipment for data
communications. Sometimes
referred to as a private network.
PVC
See
PWR 2940
A power supply for use with a
(DLS). See