Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 141)

Acronyms and Definitions
Verilink Access System 2000: Basics Glossary-21
FE LUAS Far-end Local Unavailable Second.
An unavailable second (UAS) at
the far-end CSU counted by the
local CSU.
Fiber-Distributed Data Interface (FDDI) A LAN token ring standard
developed by the ANSI X3T9.5
committee. Uses fiber optics cable
operating at 100 Mbit/s, in a dual-
ring topology (up to 500 nodes),
over a maximum distance of 100
kilometers. FDDI was originally
defined for multimode fiber,
although specifications now exist
for copper (CDDI) and single mode
fiber.
firmware A set of instructions embedded
into a semiconductor (any software
residing in silicon).
flash See EPROM.
fractional E1 A E1 in which less than 31 DS0
timeslots have been leased.
fractional T1 A T1 in which less than 24 DS0
timeslots have been leased.
fractional T3 A T3 in which less than 28 DS1
timeslots have been leased.
FRAD See Frame Relay Access Device
(FRAD) .
frame A group of bits sent serially (one
bit at a time) over a digital network
conforming to a standard format
(for example, number of bits per
frame, speed parameters, and
timeslot apportionment). Each
frame is an organized unit that
aids the transmitting and receiving
ends of the network to
synchronize.
frame alignment signal (FAS) A bit pattern used by the receiving
end to locate the beginning of a
frame.
frame alignment signal error rate
(FASER)
Tracks how often frame alignment
signals are in error within a
specific time interval.
frame bit error (FE) An error in the received framing bit
pattern.
frame bit errored second (FBES) The number of whole seconds that
a framing bit error (LOF) has
occurred.
frame relay A network switching protocol that
uses small packets and requires
less error checking than traditional
forms of packet switching.