COMPUTER NETWORKS Jisha Das

NETWORK 2 or more computers that are linked: to share resources exchange files allow electronic communications

2 or more computers that are linked:

to share resources

exchange files

allow electronic communications

Computers on a network maybe linked through : Cables Telephone lines Radio waves Satellites Infra red light beams

Computers on a network maybe linked through :

Cables

Telephone lines

Radio waves

Satellites

Infra red light beams

TYPES OF NETWORK LAN : is a network that is confined to a small area. WAN : connect larger geographic areas. MAN: connect within a city or metropolis

LAN : is a network that is confined to a small area.

WAN : connect larger geographic areas.

MAN: connect within a city or metropolis

Internet : is a network that links hundreds of thousands of networks all over the world, which in turn service individual PC’s or host computers. Intranet : private networks using Internet networking standards and Web technology.

Internet : is a network that links hundreds of thousands of networks all over the world, which in turn service individual PC’s or host computers.

Intranet : private networks using Internet networking standards and Web technology.

NETWORK COMPONENTS Hardware Transmission facilities Access devices: Ethernet Card Devices that repeat transmitted signals HUB Software Protocols Device drivers Communication software

Hardware

Transmission facilities

Access devices: Ethernet Card

Devices that repeat transmitted signals HUB

Software

Protocols

Device drivers

Communication software

Ethernet Card

HUB HUB

USER VIEW OF COMPONENTS Servers Clients Circuit

Servers

Clients

Circuit

TOPOLOGY How computers are connected together. STAR TOPOLOGY RING TOPOLOGY BUS TOPOLOGY

How computers are connected together.

STAR TOPOLOGY

RING TOPOLOGY

BUS TOPOLOGY

STAR TOPOLOGY

BUS TOPOLOGY

Communication Media Unshielded Twisted Pair (UTP) Cable Coaxial Cable Fiber Optic Cable Wireless

Unshielded Twisted Pair (UTP) Cable

Coaxial Cable

Fiber Optic Cable

Wireless

Wireless Microwave Terrestrial Satellite Radio Infrared Lasers

Microwave

Terrestrial

Satellite

Radio

Infrared

Lasers

Protocols rules that govern the communication process

OSI REFERENCE MODEL

Defined by the international standard organisation A set of protocols in a hierarchical order which all std. protocols follow. A reference, not mandatory 7 layers

Defined by the international standard organisation

A set of protocols in a hierarchical order which all std. protocols follow.

A reference, not mandatory

7 layers

PHYSICAL LAYER : nature of & specifications of physical components DATA LINK LAYER : Organizing the data NETWORK LAYER : where to sent the message TRANSPORTATION LAYER : reliable transmission of data PRESENTATION LAYER: user interfaces across different platforms APPLICATION LAYER: sets up standards for applications.

PHYSICAL LAYER : nature of & specifications of physical components

DATA LINK LAYER : Organizing the data

NETWORK LAYER : where to sent the message

TRANSPORTATION LAYER : reliable transmission of data

PRESENTATION LAYER: user interfaces across different platforms

APPLICATION LAYER: sets up standards for applications.

REFERENCES http://fcit.usf.edu/Network/ http://www.webopedia.com/quick_ref/OSI_Layers.asp www.wikipedia.com Sir’s ppt on NETWORKS

http://fcit.usf.edu/Network/

http://www.webopedia.com/quick_ref/OSI_Layers.asp

www.wikipedia.com

Sir’s ppt on NETWORKS