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Network Access Identifier (NAI) uniquely identifies a subscriber in an administrative network domain (or realm).


Name Server Record

A name server record contains a DNS servers IP address.


Name Resolution

The allocation of an IP address to a host name. See also DNS.


NAT (Network Address Translation)

The translation of an Internet Protocol address used within one network to a different IP address known within another network - see also SUA.


NAT - Global

This refers to the packet address (source or destination) as the packet travels on the WAN.


NAT - Inside

This refers to the host on the LAN.


NAT - Local

This refers to the packet address (source or destination) as the packet travels on the LAN.


NAT -Outside

This refers to the host on the WAN.


NAT over IPSec

See Virtual Address Mapping.


NAT Server Set

A NAT server set is a list of inside servers (behind NAT on the LAN) that you can make visible to the outside world.


NAT Traversal (UPnP)

UPnP NAT traversal automates the process of allowing an application to operate through NAT. UPnP network devices can automatically configure network addressing, announce their presence in the network to other UPnP devices and enable exchange of simple product and service descriptions.


NAT Traversal (VPN/IPSec)

NAT traversal allows IPSec tunnels using the ESP protocol to pass through NAT-enabled routers.



A network-based anti-virus (NAV) scanner is software on a gateway device that protects the network from virus attacks.


Navigator Key

A navigator key (also simply referred to as a navigator) is a control key often found on mobile devices such as cellphones and PDAs. The navigator usually allows the operator to scroll in four directions (up, down, left and right).



A Windows specification for how communication protocol programs (such as TCP/IP) and network device drivers should communicate with each other.



An IPv6 device uses Neighbor Discovery Protocol (NDP) to discover other IPv6 devices and track their reachability in a network.



Network Elements (NE) are part of a Network Management System (NMS). They represent a physical piece of equipment on the network, the components of a device on the network, or parts of the network itself.


Negotiation Mode

The phase 1 negotiation mode determines how the Security Association (SA) will be established for each connection through IKE negotiations. See also Aggressive Mode and Main Mode.


Neighbor BS List

WiMAX base stations (BSes) broadcast a list of neighbor base stations to mobile stations (MSes). MSes use it to scan the BSes and choose one as its target BS before a handover process takes place.


Neighbor Cache

An IPv6 neighbor cache is similar to a MAC address table in IPv4, which contains the link-layer addresses (MAC addresses), associated IP addresses and the status of the neighboring devices.


Neighbor Discovery Protocol

Neighbor Discovery Protocol (NDP) is a protocol used to discover other IPv6 devices and track neighbor reachability in a network. When a neighbor is “reachable”, it means the neighbor device sent a neighbor advertisement message in response to a multicasting neighbor solicitation message sent by your device.



Network Basic Input/Output System (NetBIOS) is an extension of the DOS BIOS that enables a computer to connect to and communicate with a LAN. For some dial-up services such as PPPoE or PPTP, NetBIOS packets can cause unwanted calls. However, it may sometimes be necessary to allow NetBIOS packets to pass through to the WAN in order to find a computer.


NetBIOS name

A Network Basic Input/Output System name is the Windows computer name of a computer.



Any time you connect two or more computers together, allowing them to share resources, you have a computer network. Connect two or more networks together and you have an internet. Also: a series of computers or devices connected for the purpose of data sharing, storage, and/or transmission between users.


Network-Attached Storage

An NAS is a device connected to a network that provides additional storage space to network users and groups. Generally, NAS solutions most often serve as backup destinations because they come with multiple hard disk drives and numerous redunancy features in case any given drive fails.


Network Address Translation

Network Address Translation (NAT) maps an IP address within one network to a different IP address in another network. For example, you could use a NAT router to map one IP address from your ISP to multiple private IP addresses for the devices in your home network.


Network Connectivity
The physical (wired or wireless) and logical (protocol) connection of a computer network or an individual device to a network, such as the Internet or a LAN.


Network Contention

Network contention describes a situation when two or more networked devices attempt to use the same medium simultaneously.


Network Entry and WiMAX

Network entry is the procedure that mobile stations have to take to join a WiMAX network.


Network Policy

A network policy identifies the devices behind the IPSec routers at either end of a VPN tunnel and specifies the authentication, encryption and other settings needed to negotiate a phase 2 IPSec SA.


Network Storage Appliance

A Network Storage Appliance (NSA) is a device connected to a network that provides additional storage space to network users and groups. NSA devices often serve as backup destinations because they come with multiple hard disk drives and numerous redundance.



Network File System (NFS) is a protocol most commonly used on Unix-like systems in order to share files across the network.



A board that provides network communication capabilities to and from a computer system. Also called an adapter.



A non-line-of-sight (NLOS) signal is one whereby a transmitter can transfer data to a receiver without a direct visual line of sight (i.e., through a solid object such as a building's walls, or by reflecting off other objects). See also Signal Absorption and Line-of-Sight (LOS).



The NMK is a password defined in the HomePlug AV standard. HomePlugAV compatible powerline adapters use the same NMK to recognize and communicate with each other over the powerline network.



A NMS is used to manage a network and the communication between Network Elements (NE).


NNTP (Network News Transfer Protocol)          

The protocol used to connect to Usenet groups on the Internet.



A network junction or connection point, typically a computer or work station.


Non-volatile memory

Non-volatile memory (sometimes abbreviated to NVM) is memory that does not require power to maintain data storage (such as ROM or Flash memory).


Northbound Interface

This is part of an Element Management System (EMS). It lets a Network Management System (NMS) control the EMS, as well as the Network Elements (NE) the EMS controls.



With ABR, the Number of Resource Management (NRM) is the maximum number of cells a source may send for each RM cell that it sends.


NT mode in ISDN

A NT (Network Terminal) is a termination device between TEs and ISDN central office (CO). The NT is responsible for performance, monitoring, power transfer, and multiplexing of the channels. You must connect a TE device (configured as TE mode) to a NT device (configured as NT mode) to access an ISDN network.



NTP stands for Network Time Protocol. It is employed by devices connected to the Internet in order to obtain a precise time setting from an official time server. These time servers are accurate to within 200 microseconds.



See Auto-Negotiation.


N-wire Mode


The n-wire mode allows you to physically bundle two or four G.SHDSL ports into a single 4-wire or 8-wire G.SHDSL connection. This can increase the reach of G.SHDSL or give increased bandwidth when connecting to 4-wire mode G.SHDSL modems or another DSLAM.