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N
NAK
NAK stands for negative
acknowledgment. In data communications a node will send a NAK to another
node to indicate the frame should be retransmitted due to a problem during
transmission or a problem at the receiver.
Native Mode
Native
mode refers to a mode of transmitting data where the information is sent in
its original form. In other words the data is not compressed or altered in
any form.
NAU
NAU stands for
Network Addressable Unit. This is an IBM SNA term used to collectively
describe PUs, LUs, and SSCPs. They are called network addressable units
because they have addresses and can communicate with one another. NAU
services are simply the services provided the NAUs in the nodes, together
with the transmission control, data flow control, and function management
layers of SNA. NAU services include establishing connections, managing the
end-to-end flow of data across the connections, and providing certain
application and user services and overall management of the network.
NDIS
NDIS stands for
Network Driver Interface Specification. The NDIS standard was developed by
Microsoft and 3Com to provide a common interface between NIC drivers and
networking protocols. The functionality of NDIS is comparable to ODI (Open
Data-link Interface).
Net
Net is short for
network. There are many different types of networks in data communications.
Examples of networks are local area networks (LANs), wide area networks
(WANs), metropolitan area networks (MANs) and point-to-point networks. All
of these networks are discussed in this system. "The Net" is a
common reference to the Internet.
NetBEUI
NetBEUI stands
for NetBIOS Extended User Interface. It is Microsoft's LAN Manager
Transport Layer driver used in LAN Manager. IBM developed NetBEUI in 1985
as a network transport protocol for LANs. In relation to the OSI model,
NetBEUI is a Network and Transport Layer protocol. NetBIOS and NetBEUI are
integrated in the LAN environment to provide an efficient communications
system.
NetBIOS
NetBIOS stands
for Network Basic Input/Output System. It is a software system developed by
Systek and IBM that has become the de facto standard for application
interface to LANs. It operates at the Session Layer of the OSI protocol
stack. Applications can call NetBIOS routines to carry out functions such
as data transfer across a LAN.
NETID
Each host on a
TCP/IP Internet is assigned a unique 32-bit Internet address that is used
in all communication with that host. Conceptually each ID is a pair of
addresses, the NETID and the HOSTID. NETID identifies a network and HOSTID
identifies a host on that network. A sample IP address format (class A) is
shown in the IP Addressing diagram (There are actually five classes of IP
addresses used for different size networks). Gateways base routing
decisions on the NETID portion of the address. Since some machines (such as
routers) have two connections to a network, IP addresses specify connection
to a network and not an individual machine (HOSTID 0). A broadcast
transmission uses a HOSTID of all 1s.
NetWare
NetWare is Novell's
distributed, multitasking Network Operating System (NOS) is designed to
provide and coordinate all network services, including file directory
services, print services, software protection services, network security,
and messaging. PCs and workstations on the network use the Advanced NetWare
Core Protocol (NCP) to communicate with the operating system to obtain
network services for their local applications.
Network Address
A
network address is the unique way each node or station on a network is
identified. An example of a network address would be an IP address such as
144.49.4.1. A network address typically relates to protocols found at the
Network Layer of the OSI model.
Network Operating System
The
software that manages server operations and provides services to clients is
called the Network Operating System (NOS). The NOS manages the interface
between the network's underlying transport capabilities and the
applications resident on the server.
NIC
NIC stands for
Network Interface Card. It is the computer card that attaches a computer to
a network. NIC also stands for network information center. Originally there
was only one, located at SRI International and tasked to serve the ARPANET
(and later DDN) community. Today, there are many NICs, operated by local,
regional, and national networks all over the world. Such centers provide
user assistance, document service, training, and much more.
NFS
NFS stands for
Network File System. It is a file management system used with TCP/IP and
UNIX systems. It was originally developed by Sun Microsystems. NFS can now
be found on various systems and platforms, especially PC-based platforms
that utilized the TCP/IP protocol. NFS is available as a NetWare Loadable
Module (NLM) for allowing UNIX systems access to NetWare file servers.
NOC
NOC stands for Network Operations Center.
Any center tasked with the operational aspects of a production network.
These tasks include monitoring and control, trouble-shooting, user
assistance, and so on.
Node
Generically
speaking, a node is any device connected to a network. Typically nodes are
thought of as workstations or PCs which have communication capabilities.
Normal Response Mode
Normal
Response Mode is one of three types of data transfer modes in the HDLC
family of protocols:
- Normal Response Mode (NRM). Used in the
unbalanced configuration, secondary may only respond to a poll from
the primary station.
- Asynchronous Balanced Mode (ABM). Either
station may initiate transmission (balanced configuration).
- Asynchronous Response Mode (ARM). Either
station may initiate transmission but one station has responsibility
for line maintenance such as error recovery.
Null Modem
A null
modem is used to hook two computers together without the use of modems.
Using a standard modem cable (RS232) from each of the two computers you can
configure them so that the two computers can communicate.
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