computer science illuminated chapter 15

Computer network

A

collection of computing

devices connected so

that they can communicate

and share resources

Wireless

A network

connection made without

physical wires

Node (or Host)

Any

addressable device

attached to a network

Data transfer rate (also

bandwidth)

The speed

with which data is

moved from one place to

another on a network

Protocol

A set of rules

that defines how data is

formatted and processed

on a network

Client/server model

A distributed approach

in which a client makes

requests of a server and

File server

A computer

dedicated to storing and

managing files for

network users

Web server

A

computer dedicated to

responding to requests

for Web pages

Local-area network

(LAN)

A network

connecting a small

number of nodes in a

close geographic area

Ring topology

A LAN

configuration in which

all nodes are connected

in a closed loop

Star topology

A LAN

configuration in which a

central node controls all

message traffic

Bus topology

A LAN

configuration in which

all nodes share a

common line

Ethernet

The industry

standard for local-area

networks, based on a

bus topology

Wide-area network

(WAN)

A network

connecting two or more

local-area networks

Gateway

A node that

handles communication

between its LAN and

other networks

Internet

A wide-area

network that spans the

planet

Metropolitan-area

network (MAN)

A

network infrastructure

developed for a large

city

Internet backbone

A

set of high-speed

networks carrying

Internet traffic

Internet service

provider (ISP)

A

company providing

access to the Internet

Phone modem

A

device that converts

computer data into an

analog audio signal and

back again

Digital subscriber line

(DSL)

An Internet

connection made using a

digital signal on regular

phone lines

Cable modem

A

device that allows

computer network

communication using the

cable TV hookup in a

home

Broadband

Network

technologies that generally

provide data transfer

speeds greater than 128

bps

Download

Receiving

data on your home

computer from the

Internet

Upload

Sending data

from your home

computer to a destination

on the Internet

Packet

A unit of data

sent across a network

Packet switching

The

approach to network

communication in which

packets are individually

routed to their destination,

then reassembled

Router

A network

device that directs a

packet between networks

toward its final destination

Repeater

A network

device that strengthens

and propagates a signal

along a long communication

line

Proprietary system

A

system that uses technologies

kept private by

a particular commercial

vendor

interoperability

The

ability of software and

hardware on multiple

machines and from

multiple commercial

vendors to communicate

Open system

A system

that is based on a

common model of

network architecture and

an accompanying suite

of protocols

Open Systems Interconnection

Reference

l

A seven-layer

logical breakdown of

network interaction to

facilitate communication

standards

Protocol stack

Layers

of protocols that build

and rely on each other

Transmission Control

Protocol (TCP)

The

network protocol that

breaks messages into

packets, reassembles

them at the destination,

and takes care of errors

Internet Protocol (IP)

The network protocol

that deals with the

routing of packets

through interconnected

networks to the final

destination

TCP/IP

A suite of

protocols and programs

that support low-level

network communication

User Datagram

Protocol (UDP)

An

alternative to TCP that

achieves higher transmission

speeds at the

cost of reliability

Ping

A program used

to test whether a particular

network computer is

active and reachable

Traceroute

A program

that shows the route a

packet takes across the

Internet

Port

A numeric designation

corresponding to

a particular high-level

protocol

MIME type

A standard

for defining the format of

files that are included as

e-mail attachments or on

Web sites

Firewall

A gateway

machine and its software

that protects a network

by filtering the traffic it

allows

Access control policy

A set of rules established

by an organization that

specify what types of

network communication

are permitted and

denied