Networks can be classified by:
SCALE:

L A N
LOCAL AREA NETWORK

WAN
WIDE AREA NETWORK

Backup

to back up a file means

information theft

ENCRYPTION

unauthorized access

unauthorized use

Computer virus

worm

Trojan horse

ROOT KIT

COMPUTER
SECURITY
RISK

CYBER CRIME

SECONDARY
STORAGE

STORAGE MEDIUM

Capacity

storage device

Why use Secondary Storage?

Hard Disk

Cylinder concept

Formatting

Fixed Hard Drive

Portable Hard Drive

RAID
redundant array
of
independent
disks

network attached storage
(NAS)

Access Time

Access time = Rotational Delay + Seek Time

optical disc

Optical Discs

CD-ROM

CD-R

CD-RW

magnetic tape

Magnetic Tape

Magnetic tape is a large capacity,

Types of Access
Sequential Access

Types of Access:

Random Access

Types of Access
Devices can also be classified as sequential access or random access

Advantages of a Network:

Networks may be classified by

SCALE:
Personal Area Network

(PAN)

SCALE;
Local Area Network

(LAN)

scale:

Campus Area Network

(CAN)

scale:
Metropolitan Area Network

(MAN)

scale:

Wide Area Network

(WAN)

Networks:
collection methods

Ethernets

Network Topology

Classification of Networks –

Network Topology

Classification of Networks –

Communication Standards & Protocol

Classification of Networks –

Communication Standards & Protocol

TCP/ IP

Computer communications

A communications device is

Communications software consists

bandwidth

Latency

Transmission media

Broadband media

inter
network

three variants of
inter network,

Intranets and extranets may or may not have connections to the Internet.

An intranet

An extranet is a network or
inter network

Internet

Classification of Networks:

Ethernet

Classification of Networks:
Standards and Communication

Token Ring