NETWORKING

NETWORKS

TELECOMMUNICATIONS

Two or more computers communicating

Long distance communications

2 Network Classifications

• Client server

• Peer to Peer

Physical definitions

2 Network Classifications

• LAN

• WAN

Distance definitions

LOCAL AREA NETWORK

WIDE AREA NETWORK

NETWORKS

LAN

LOCAL AREA NETWORK

LAN Characteristics

• TOPOLOGY

Bus

Star

Ring

• Protocol

Polling

CSMA/CD

Token Ring

NETWORKS

WAN

WIDE AREA NETWORK

Long distance communication

Generally not privately owned

MAJOR FUNCTIONS

Make long distance communication seem local

Standardize network interface

Standardize procedures for sending information

Govern error transmission

Govern security

Govern integrity of data

NETWORK COMPONENTS

• Computers

• Media

• Software

• Network

connections

• Satellites

• Microwave

stations

• Multiplexer – combines many data streams into a single stream

Additional Media Type

Electromagnetic waves

A type of radio wave

Used by satellites

Used by portable computers

MICROWAVE STATIONS

Needs a direct sight line

SATELLITES

WAN TOPOLOGIES

1. Point to Point

2. Multidrop

3. Mesh

4. Star

Point to Point

Direct Connection

Between Computers

Advantage

No Waiting

Disadvantage

Expensive to connect

Adding new computer

Multidrop

C om p u ter2 C om p u ter3

C om p u ter1

Hierarchical

Between Concentrator

Advantage

No Waiting

Direct connections

Disadvantage

May find delays if going outside

the predefined connections

Adding new computer

Star

Central Point

Time Sharing Host

Advantage

Centralized control

(security)

Disadvantage

Centralized control

(delays)

Mesh

Individual Routes

Needs a router

Advantage

No Waiting

Disadvantage

Connections

(solutions – servers)

Other types of NETWORKS

Public access networks (government)

VAN – value added network

(extra feature – faxes)

Private area networks (Sears)

Public Data Network

(TYMNET)

Wide Area NetworksEnvironments

PSTNPublic Switch

Telephone Network

TYPES of Lines

Private– Direct– Expensive

Tie line– Dedicated without the use of the PSTN

Exchanges– Foreign/private

800 numbers

DDNdata digital network

Only transmits DIGITAL information

PSNpacket switching network

Sends information in groups called PACKETS

ISDNintegrated services

digital network

Sends only digital signals

Transmits HIGH VOLUME of data

Can use the Internet while using the phone line – use of two phone lines

DSLDigital Subscriber Line

Translates digital signals to analog

Transmits HIGHER VOLUME of data than ISDN

Spreads analog signal over a wide range of frequencies