Network Everywhere NR041 User Manual page 42

Router - Protocol-dependent device that connects subnetworks together.
Routers are useful in breaking down a very large network into smaller subnet-
works; they introduce longer delays and typically have much lower throughput
rates than bridges.
Server - Any computer whose function in a network is to provide user access
to files, printing, communications, and other services.
SMTP (Simple Mail Transfer Protocol) - The standard e-mail protocol on the
Internet. It is a TCP/IP protocol that defines the message format and the mes-
sage transfer agent (MTA), which stores and forwards the mail.
SNMP (Simple Network Management Protocol) - A widely used network
monitoring and control protocol. Data is passed from SNMP agents, which are
hardware and/or software processes reporting activity in each network device
(hub, router, bridge, etc.) to the workstation console used to oversee the net-
work. The agents return information contained in a MIB (Management
Information Base), which is a data structure that defines what is obtainable
from the device and what can be controlled (turned off, on, etc.).
Software - Instructions for the computer. A series of instructions that performs
a particular task is called a "program." The two major categories of software are
"system software" and "application software." System software is made up of
control programs such as the operating system and database management sys-
tem (DBMS). Application software is any program that processes data for the
user.
A common misconception is that software is data. It is not. Software tells the
hardware how to process the data.
SOHO (Small Office/Home Office) - Market segment of professionals who
work at home or in small offices.
Static IP Address - A permanent IP address that is assigned to a node in a
TCP/IP network.
Static Routing - Forwarding data in a network via a fixed path. Static routing
cannot adjust to changing line conditions as can dynamic routing.
Storage - The semi-permanent or permanent holding place for digital data.
STP (Shielded Twisted Pair) - Telephone wire that is wrapped in a metal
sheath to eliminate external interference.
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Network Everywhere Series
™
Cable/DSL 4-Port Router
Subnet Mask - The method used for splitting IP networks into a series of sub-
groups, or subnets. The mask is a binary pattern that is matched up with the IP
address to turn part of the host ID address field into a field for subnets.
Swapping - Replacing one segment of a program in memory with another and
restoring it back to the original when required.
Switch – 1. A data switch connects computing devices to host computers,
allowing a large number of devices to share a limited number of ports. 2. A
device for making, breaking, or changing the connections in an electrical cir-
cuit.
TCP (Transmission Control Protocol) - A method (protocol) used along with
the IP (Internet Protocol) to send data in the form of message units (datagram)
between network devices over a LAN or WAN. While IP takes care of handling
the actual delivery of the data (routing), TCP takes care of keeping track of the
individual units of data (called packets) that a message is divided into for effi-
cient delivery over the network. TCP is known as a "connection oriented" pro-
tocol due to requiring the receiver of a packet to return an acknowledgment of
receipt to the sender of the packet resulting in transmission control.
TCP/IP (Transmission Control Protocol/Internet Protocol) - The basic com-
munication language or set of protocols for communications over a network
(developed specifically for the Internet). TCP/IP defines a suite or group of
protocols and not only TCP and IP.
Telnet - A terminal emulation protocol commonly used on the Internet and
TCP/IP-based networks. It allows a user at a terminal or computer to log onto
a remote device and run a program.
TFTP (Trivial File Transfer Protocol) - A version of the TCP/IP FTP protocol
that has no directory or password capability.
Throughput - The amount of data moved successfully from one place to anoth-
er in a given time period.
Topology - A network's topology is a logical characterization of how the
devices on the network are connected and the distances between them. The
most common network devices include hubs, switches, routers, and gateways.
Most large networks contain several levels of interconnection, the most impor-
tant of which include edge connections, backbone connections, and wide-area
connections.
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