Filter
Top Products
Glossary
GL-9
Cisco 10008 Router Hardware Installation Guide
OL-0659-13
Multiplexing
An activity in which multiple logical signals are transmitted simultaneously across a single physical
channel.
Multiprotocol Label
Switching
See MPLS.
N
NEBS
Network Equipment Building Systems. The Telcordia (formerly Bellcore) requirements for equipment
deployed in a central office environment. Covers spatial, hardware, crafts person interface, thermal, fire
resistance, handling and transportation, earthquake and vibration, airborne contaminants, grounding,
acoustical noise, illumination, EMC, and ESD requirements.
Network Equipment
Building Systems
See NEBS.
Network
termination unit
See NTU.
Nonvolatile RAM
See NVRAM.
NTU
Network terminating unit. The network equipment that connects directly to the data terminal
equipment.
NVRAM
Nonvolatile RAM. RAM that retains its contents when a unit is powered off.
O
OC
Optical carrier. A series of physical protocols (OC-1, OC-2, OC-3, and so forth), defined for SONET
optical signal transmissions. OC signal levels put STS frames onto fiber-optic lines at a variety of
speeds. The base rate is 51.84 Mbps (OC-1); each signal level thereafter operates at a speed divisible
by that number (thus, OC-3 runs at 155.52 Mbps).
ODL
Optical data link.
OIR
Online insertion and removal. Feature that permits the addition, replacement, or removal of cards
without interrupting the system power, entering console commands, or causing other software or
interfaces to shut down. Same as hot swapping.
Online insertion and
removal
See OIR.
Optical carrier
See OC.
Optical fiber
See Fiber-optic cable.