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