Appendix C: WAN Terms and Acronyms
C-4
HSIM-W87 User’s Guide
LCV —
Line Coding Violation, a count of both BPVs and EXZs
occurring over the accumulation period. An EXZ increments the LCV by
one regardless of the length of the zero string.
LEX —
LAN Extender, a Cisco Systems protocol used to internetwork a
host-based router with a remote switch.
LMP —
Link Management Protocol, used in Frame Relay. Allows the
device to gather information about the DLCIs (Data Link Connection
Identifiers) See T1.617-D, Q.933-A.
Local Timing —
Timing for digital transmission circuit is internally
generated by a source within the equipment. Usually used for short haul
private lines. In this case one CSU must be set for Local (internal) timing
and the CSU at the other end of the line must be set for Loop (recovered)
timing to create a master-slave situation.
Loop Timing —
Timing for digital transmission circuit is recovered
from the received data, not generated internally by a source within the
equipment. This is the typical situation when using public lines. Also may
be referred to as clock slave timing.
LLB —
Line Loop Back, a full T1 loopback on D4 or ESF framed lines.
LOS —
Loss of Signal, DS3 signal where a predetermined amount of
pulses without polarity are deemed a defect.
M13 —
(pronounced M-one-three) DS1 into a DS3 multiplexer.
MIM —
Media Interface Module, Cabletron Systems products designed
to fit in a Multi Media Access Center (MMAC) hub.
MUX —
Multiplexer, an electronic device that allows two or more
signals to pass over one communications circuit.
NI —
Network Interface.
OOF —
Out of Frame, a DS3 OOF defect is detected when any three or
more errors in sixteen or fewer consecutive F-bits occur within a DS3
M-frame. An OOF defect may also be called a Severely Errored Frame
(SEF) defect. An OOF defect is cleared when reframe occurs. A DS3 Loss
of Frame (LOF) failure is declared when the DS3 OOF defect is
consistent for 2 to 10 seconds. The DS3 OOF defect ends when reframe
occurs. The DS3 LOF failure is cleared when the DS3 OOF defect is
absent for 10 to 20 seconds.
