N-O0-A | B | C-Cn | Co-Cz | D | E | F-G | H-I | J-L | M | N-O | P-Q | R | S | T | U-Z
0-A | B |
C-Cn | Co-Cz | D | E | F-G | H-I | J-L | M | N-O | P-Q | R | S | T | U-Z
- NA: See Numerical Aperture
- NAK: See Negative
- Name Binding Protocol: (NBP)
AppleTalk protocol for translating devices names to addresses.
- Nanometer: (nm) One billionth of a meter = 10-9
- Nanosecond: One billionth of a second.
- National Electrical Code: (NEC) which defines building
flammatory requirements for indoor cables.
Television System Committee: (NTSC) One of the standards for television
signals, developed in 1941. Has 486 visible horizontal lines. Sometimes
referred to as 480i
- NBP: See Name Binding
- NCC: See Network Control
- NDIS: See Network Driver Interface
- Near End Crosstalk: (NEXT)
Crosstalk measured at the end from which the disturbing signal is
- NEC: See National Electrical
- Negative Acknowledgment: (NAK) A data link
control character transmitted by the receiver as a negative response to the
sender. The response may relate to data or control information.
National Electrical Manufacturers Association.
- Neoprene: A synthetic
rubber with good resistance to oil, chemical, & flame. Also called
- Net Id: See Network
- NetBIOS: See Network Basic
- Netview: An IBM mainframe network management
product that integrated the function of several earlier IBM network management
- NetWare: Novell's network operating system using IPX
(Internetwork Packet Exchange) & SPX (Sequential Packet Exchange)
- Network: A set of communication channels inter-connecting
several devices and/or locations.
- Network Architecture: A description
of data formats & procedures used for communication between nodes.
- Network Basic Input/Output System: (NetBIOS) A widely-used
protocol governing data exchange & network access.
- Network Control Center: (NCC) Any centralized network
diagnostic & management station or site, such as that of a packet-switching
- Network Driver Interface Specification:
(NDIS) Specification for a generic device driver for network interface cards
that are independent of hardware & protocol.
File System: (NFS) Sun Microsystems' network operating system based on
- Network Identification: (Net Id)
The first part of the 32-bit IP address.
Information Frame: (NIF) determines which FDDI station is upstream & which
is downstream when two stations are talking.
- Network Interface Card:
See Network Interface Controller
- Network Interface Controller: (NIC) Electronic circuitry
that connects a workstation to a network, usually a card that fits into one of
the expansion slots inside a personal computer. It works with the network
software & computer operating system to transmit & receive messages on the
- Network Interface Module: See Adapter Card
- Network Layer: Layer 3 of the
OSI (Open Systems Interconnection) model; it defines protocols governing data
- Network Loadable Module: (NLM) An
application or driver that resides on a NetWare server to provide additional
resource management capabilities.
- Network Management
System: (NMS) Systems equipment used in monitoring, controlling & managing
a data communications network.
- Network Operating
Systems: (NOS) Software that provides users with a variety of data
communication service including file sharing, electronic mail, security systems
& methods for connecting network systems.
- Network Topology: The
arrangement of nodes usually forming a star, ring, tree, or bus
- NEXT: See Near End
- NFS: See Network File
- NIC: See Network Interface
- NIF: See Network Information
- NIM: (Network Interface Module) See Adapter Card
- NLM: See Network Loadable Module
- NM: See Nanometer
- NMS: See Network
- Nodes: A device connected to the network which
can be addressed by other nodes.
- Noise: In a cable or circuit, any
extraneous signal which tends to interfere with the signal normally present in
or passing through the system.
- Non-Return to Zero:
(NRZ) Binary coding transmission with no return to neutral state after each bit
- Nondedicated server: A node on which user
applications are available while network resources maintenance applications
execute in the background.
- NOS: See Network Operating
- NRZ: See Non-Return to
- NTSC: See National Television System
- Null Modem: A device that connects two DTE's directly
by emulating the physical connections of a DCE.
- Numerical Aperture: (NA) A measure of the angular
acceptance for a fiber. It is approximately the sine of the half angle of the
- Nylon: An abrasion-resistant thermoplastic with good
- ODI: See Open Datalink
- Ohm: The electrical unit of resistance. The value of
resistance through which a potential difference of one volt will maintain a
current of one ampere.
- Open Datalink Interface:
(ODI) a standard interface specification developed by Novell to enable PC
adapter cards to run multiple protocol stacks.
Shortest Path First: (OSPF) A distribution algorithm & routing protocol
used by routers to compute the best path to be used to forward packets through
an internetwork. It is derived from the OSI Shortest Path First (SPF)
- Open System: A networked computer or software which can
easily be extended or enhanced with precuts from another vendor or technology
source. Open systems usually imply the use of standard, replaceable protocols &
hardware components, & well-defined interfaces.
Systems Interconnection: (OSI). A standard developed by the ISO
(International Standards Organization) for a logical network operations
- Operating System: A program which controls the operation,
scheduling & various other related functions of other programs within the
- Optical Disk: A very high-density information storage
medium that uses light to read & write digital information. (CD and DVD are
- Optical Fiber Cable: An assembly
consisting of one or more optical fibers (glass or plastic) with strengthening
material & an outer jacket.
- Optical Fiber Duplex Connection: A mated
assembly of two duplex connectors & a duplex adapter.
- Optical Fiber
Duplex Connector: A mechanical media termination device designed to
transfer optical power between two pairs of optical fibers.
- Optical Time
Domain Reflection: An instrument that measures transmission characteristics
of fiber by sending a pulse of light down the fiber & measuring the light
scattered across the length & reflected back from the end as a function of
- OS/2: The third generation operating system developed by IBM &
Microsoft for use with the Intel 80286 & 80386 microprocessors. Unlike its
predecessor (PC MS-DOS), OS/2 is a multitasking operating software that will
run on the Personal System/2. OS/2 Standard Edition is a joint Microsoft & IBM
development, while OS/2 Extended Edition is the IBM proprietary extension to
include communications & database managers.
- OSI: See Open Systems Interconnection
- OSINET: A test network,
sponsored by the National Bureau of Standards (NBS), designed to provide
vendors of products based on the OSI model a forum for inter-operability
- OSPF: See Open Shortest Path
- Overhead: In communications, all information, such as
control, routing, & error-checking characters, that is in addition to user
transmitted data; includes information that carries network status or
operational instructions, network routing information, & retransmission of user
data messages that are received in error.
- Ozone: Extremely reactive
form of oxygen, normally occurring around electrical discharges & present in
the atmosphere in small but active quantities. In sufficient concentrations it
can break down certain rubber insulation's under tension (such as a bent