NARP: NBMA Address Resolution Protocol
The NBMA Address Resolution Protocol (NARP) allows a source terminal (a host or router), wishing to communicate over a Non-Broadcast, Multi-Access (NBMA) link layer network, to find out the NBMA addresses of a destination terminal if the destination terminal is connected to the same NBMA network as the source.
Standard Organization: IETF
Reference Document: RFC 1735

NAT: Network Address Translation
Network Address Translation (NAT) is a method by which IP addresses are mapped from one group to another, transparent to end users. The need for IP Address translation arises when a network's internal IP addresses cannot be used outside the network either for privacy reasons or because they are invalid for use outside the network. Network topology outside a local domain can change in many ways.
Standard Organization: IETF
Reference Document: RFC 3022

NAU: Network Accessible Units
Network Accessible Units (NAUs) are the IBM Systems Network Architecture (SNA) components to facilitate the communication between a Transaction Program (TP) and the SNA network, formerly called "network addressable units". NAUs are unique network resources that can be accessed through unique local addresses by other network resources. SNA provides the following types of NAUs: Physical units (PU), Logical units (LU) and Control points (CP).
Standard Organization: IBM

NBFCP: NetBIOS Frames Control Protocol
NetBIOS Frames Control Protocol (NBFCP) is a network control protocol for establishing and configuring the NBF protocol over Point-to-Point Protocol (PPP) links. The NBF Control Protocol (NBFCP) is responsible for configuring, enabling, and disabling the NBF protocol modules on both ends of the point-to-point link. NBFCP uses the same packet exchange mechanism as the Link Control Protocol. NBFCP packets MUST NOT be exchanged until PPP has reached the Network-Layer Protocol phase. NBFCP packets received before this phase is reached should be silently discarded. NBFCP is only applicable for an end system to connect to a peer system or the LAN that peer system is connected to. It is not applicable for connecting two LANs together due to NetBIOS name limitations and NetBIOS name defense mechanisms.
Standard Organization: IETF
Reference Document: RFC 2097

NBMA: Non-Broadcast, Multi-Access.
Non-Broadcast Multi-Access (NBMA) network allows only data transfer from one computer to another over a virtual circuit or across a switching device. The NBMA network is the opposite of a broadcast network, on which multiple computer devices are connected through a shared cable. The typical NBMA networks are Frame Relay, ATM and X.25 networks.
Standard Organization: Novell

NBP: Name Binding Protocol
Name Binding Protocol (NBP) is the AppleTalk transport-level protocol used for translating network device names to addresses and manages the use of names on AppleTalk networks. NBP enables AppleTalk protocols to understand user-defined zones and device names by providing and maintaining translation tables that map names to their corresponding socket addresses.
Standard Organization: Apple

NBSS: NetBIOS Session Service
The NetBIOS Session Service (NBSS) is one of two ways by which applications may communicate with each other, the alternative being the NetBIOS Datagram service. The bulk of all NetBIOS traffic generated on a network occurs using the NetBIOS Session service, which utilizes TCP port 139. File and printer services are the primary user of the NetBIOS Session service. Another common use for NBSS is the networked application: Server Manager, User Manager, Event Viewer, Registry Editor, and Performance Monitor.
Standard Organization: IBM

NCP: NetWare Core Protocol
The Novell NetWare Core Protocol (NCP) manages access to the primary NetWare server resources. NCP makes procedure calls to the NetWare File Sharing Protocol (NFSP) that services requests for NetWare file and print resources. NCP is the principal protocol for transmitting information between a NetWare server and its clients.
Standard Organization: Novell

NCP: Network Control Protocols
The Network Control Protocol (NCP), a protocol in the Point-to-Point Protocol (PPP) suite, provides services in the PPP link connection process to establish and configure different network-layer protocols such as IP, IPX or AppleTalk. After a NCP has reached the opened state, PPP will carry the corresponding network-layer protocol packets. Any supported network-layer protocol packets, received when the corresponding NCP is not in the opened state, must be silently discarded. The most commonly used NCPs are IP Control Protocol (IPCP) and IPv6CP.
Standard Organization: IETF
Reference Document: RFC 3435

NCS: Network-based Call Signaling
Network-based Call Signaling（NCS), based on the Media Gateway Control Protocol (MGCP), is the VOIP signaling protocol adopted by the CableLab as a standard for PacketCable embbed clients, which is a network element that provides:
• Two or more traditional analog (RJ11) access lines to a voice-over-IP (VoIP) network.
• Optionally, one or more video lines to a VoIP network
Standard Organization: IETF

NDMP: Network Data Management Protocol
The Network Data Management Protocol (NDMP) is an open protocol for enterprise-wide network based data management. NDMP defines a network-based mechanism and protocol for controlling backup, recovery, and other transfers of data between primary and secondary storage.
Standard Organization: SNIA

NDS: NetWare Directory Services
NetWare Directory Services (NDS), based on X.400, is the Novell's directory services for Netware, Windows NT, and Unix. The NDS directory represents each network resource (user, hardware, or application) as an object of a certain class, where each class has certain properties. The directory is hierarchical, divided into branches by rules of containment.
Standard Organization: Novell

NetBEUI: NetBIOS Extended User Interface
NetBIOS Extended User Interface (NetBEUI) is an extended version of NetBIOS that lets computers communicate within a local area network. NetBEUI formalizes the frame format that was not specified as part of NetBIOS, so is sometimes called the NetBIOS frame (NBF) protocol.
Standard Organization: IBM

NetBIOS Datagram Service
The NetBIOS Datagram Service is one of two ways by which applications may communicate with each other, the alternative being the NetBIOS Session service. The NetBIOS Datagram Service provides connectionless and broadcast-oriented communications, making use of the UDP transport-layer protocol, port number 138. The Datagram service, because it uses UDP, is faster and more efficient but does not provide guaranteed delivery of packets.
Standard Organization: IBM

NetBIOS Session Service
The NetBIOS Session Service (NBSS) is one of two ways applications may communicate with each other, the alternative being the NetBIOS Datagram service. The bulk of all NetBIOS traffic generated on a network occurs using the NetBIOS Session service, which utilizes TCP port 139. File and printer services are the primary user of the NetBIOS Session service. Another common use for NBSS is the networked application: Server Manager, User Manager, Event Viewer, Registry Editor, and Performance Monitor.
Standard Organization: IBM

NetBIOS: Network Basic Input Output System
Network Basic Input Output System (NetBIOS), created by IBM originally, defines a software interface and standard methods providing a communication interface between the application program and the attached medium. NetBIOS, a session layer protocol, is used in various LAN (Ethernet, Token Ring, etc) as well as WAN environments, such as TCP/IP, PPP and X.25 networks.
Standard Organization: IBM

NetRPC: NetRemote Procedure Call
The NetRemote Procedure Call (NetRPC) protocol, a protocol in the session/presentation layer of the VINES protocol stack, is used to access VINES applications such as StreetTalk and VINES Mail. A program number and version identify all VINES applications. Calls to VINES applications must specify the program number, program version, and the specific procedure within the program, where applicable.
Standard Organization: Banyan

NetWare
NetWare is a Novell network operating system (NOS) that provides transparent remote file access and numerous other distributed network services, including printer sharing and support for various applications such as electronic mail transfer and database access. NetWare specifies the upper five layers of the OSI reference model and, and runs on any media-access protocol (Layer 2). In addition, NetWare runs on virtually any kind of computer system, from PCs to mainframes. NetWare and its supporting protocols often coexist on the same physical channel with many other popular protocols, including TCP/IP, DECnet, and AppleTalk .
Standard Organization: Novell

Network Architecture
A network architecture is a blueprint of the complete computer communication network, which provides a framework and technology foundation for designing, building and managing a communication network. It typically has a layered structure. Layering is a modern network design principle which divides the communication tasks into a number of smaller parts, each part accomplishing a particular sub-task and interacting with the other parts in a small number of well-defined ways.

Network Protocol
Network Protocols define the rules and procedures for the network communications. A protocol is a formal set of rules, conventions and data structure that governs how computers and other network devices exchange information over a network. In other words, a protocol is a standard procedure and format that two data communication devices must understand, accept and use to be able to talk to each other.

NFS: Network File System
Network File System (NFS), originally developed by Sun Microsystems and then extended by IETF, allows file sharing over network among different types of systems. In other words, NFS was designed for remote file access and sharing over network with various types of machines, operating systems, network architecture and transport protocols.
Standard Organization: SUN
Reference Document: RFC 3530

NHRP: NBMA Next Hop Resolution Protocol
NBMA Next Hop Resolution Protocol (NHRP) is used by a source station (host or router) connected to a Non-Broadcast, Multi-Access (NBMA) subnetwork to determine the internetworking layer address and NBMA subnetwork addresses of the "NBMA next hop" towards a destination station. If the destination is connected to the NBMA subnetwork, then the NBMA next hop is the destination station itself. Otherwise, the NBMA next hop is the egress router from the NBMA subnetwork that is "nearest" to the destination station.
Standard Organization: IETF
Reference Document: RFC 2332

NIS: Network Information Service
Network Information Service (NIS), previously known as Yellow Page protocol, is a directory service used for name look-up and general table enumeration. Each NIS database consists of key-value pairs, maps, and domains. NIS defines a set of key-value pairs as a map. Each map belongs to a domain that is a category of maps. This hierarchy of key-value pairs, maps, and domains provides a generic structure for modeling a database of information. An optional component to a NIS server database implementation is the NIS binder (YPbind) server. NIS uses YPbinder servers to provide addressing information about NIS database servers to potential clients.
Standard Organization: Sun

NLSP: The NetWare Link Services Protocol
The NetWare Link Services Protocol (NLSP) is a link-state routing protocol in the Novell NetWare architecture. NLSP is based on the OSI Intermediate System-to-Intermediate System (IS-IS) protocol and was designed to replace IPX RIP (Routing Information Protocol) and SAP (Service Advertisement Protocol), Novell's original routing protocols that were designed for small-scale internetworks.
Standard Organization: Novell

NLSP: Network Layer Security Protocol
Network Layer Security Protocol (NLSP) is an OSI protocol for end-to-end encryption services at the top of OSI layer 3. NLSP is derived from the Secure Data Network System (SDNS) protocol but is much more complex.
Standard Organization: ISO
Reference Document: ISO 11577

NNI: Network Node Interface
Network Node Interface (NNI), also known as Network-to-Network Interface, is the standard interface between ATM switches. The term is also used with frame relay. NNI makes network routing possible.
Standard Organization: ITU-T

NNI: Network-to-Network Interface
Network-to-Network Interface (NNI), also known as Network Node Interface, is an internal interface within a network linking two or more elements. Many technologies such as ATM (ATM PNNI), Frame Relay (Frame RElay NNI) require this type of interface for the communication between network devices.
Standard Organization: ITU-T

NNTP: Network News Transfer Protocol
Network News Transfer Protocol (NNTP) specifies a protocol for the distribution, inquiry, retrieval and posting of news articles, using a reliable stream (such as TCP port 119) server-client model. NNTP is designed so that news articles need only be stored on one (presumably central) server host, and subscribers on other hosts attached to the network may read news articles using stream connections to the news host. The Network News Transfer Protocol (NNTP) established the technical foundation for the widely used Newsgroups.
Standard Organization: IETF
Reference Document: RFC 977

Novell NetWare
Novell NetWare is a Novell network operating system (NOS) that provides transparent remote file access and numerous other distributed network services, including printer sharing and support for various applications, such as electronic mail transfer and database access. NetWare specifies the upper five layers of the OSI reference model and runs on any media access protocol (Layer 2). In addition, NetWare runs on virtually any kind of computer system, from PCs to mainframes. NetWare and its supporting protocols often coexist on the same physical channel with many other popular protocols, including TCP/IP, DECnet and AppleTalk.
Standard Organization: Novell

NPAT: Network Port Address Translation
Network Port Address Translation (NPAT), also known as Port Address Translation (PAT), is a feature of a Network Address Translation (NAT) device that translates not only IP addresses but also TCP or UDP ports between a host and port on an outside network to a host and port on an inside network. NPAT allows one single IP address to be used for many internal hosts. With NPAT one outside IP address can account for over 64000 inside hosts.
Standard Organization: IETF

NSP: Network Services Protocol
Network Services Protocol (NSP), a protocol in the DECnet suite, provides reliable virtual connection services with flow control to the network layer Routing Protocol.
Standard Organization: DEC/HP

NTP: Network Time Protocol
Network Time Protocol (NTP) is a time synchronization system for computer clocks through the Internet network. It provides the mechanisms to synchronize time and coordinate time distribution in a large, diverse internet operating at rates from mundane to light wave. It uses a returnable time design in which a distributed sub-network of time servers, operating in a self-organizing, hierarchical master-slave configuration, synchronizes logical clocks within the sub-network and to national time standards via wire or radio. The servers can also redistribute reference time via local routing algorithms and time daemons.