NetworkingNetworking

Session 2Session 2

ByBy

AravindanAravindan

History of networkHistory of network

We just need to thanks to “Sputnik” and “Soviet We just need to thanks to “Sputnik” and “Soviet Union “Union “

Sputnik was the first man made satellite Sputnik was the first man made satellite launched in the year 1957.It was launced by launched in the year 1957.It was launced by Soviet UnionSoviet Union

In order to compete them US president In order to compete them US president “Eisenhower” launched Advanced Research “Eisenhower” launched Advanced Research Projects Agency (ARPA) in 1958Projects Agency (ARPA) in 1958

ContiConti In 1958 computers were enormous devices that In 1958 computers were enormous devices that

filled entire roomsfilled entire rooms

In those years computer only read magnetic In those years computer only read magnetic tape or punch cards, and there was no way to tape or punch cards, and there was no way to network computers togethernetwork computers together

ARPA's goal was to link different computers ARPA's goal was to link different computers together, in order to decentralize information together, in order to decentralize information storagestorage

ContiConti In 1968, ARPA sent out a Request for Quotation In 1968, ARPA sent out a Request for Quotation

(RFQ) to several institutions, asking for bids on (RFQ) to several institutions, asking for bids on creating the first wide area network.creating the first wide area network.

Finally BBN(Bolt, Beranek and Newman) wons Finally BBN(Bolt, Beranek and Newman) wons the bid and designed Interface Message the bid and designed Interface Message Processors (IMPs) Processors (IMPs)

This IMP's open communication between four This IMP's open communication between four different computers running on four different different computers running on four different operating systems.They called this network as operating systems.They called this network as ARPANETARPANET

Network Control ProtocolNetwork Control Protocol

As ARPANET use 4 different operating system As ARPANET use 4 different operating system the system's designers had to come up with a the system's designers had to come up with a common set of rules the network would follow in common set of rules the network would follow in order for the computers to communicate with order for the computers to communicate with each other without crashing the other systemeach other without crashing the other system

Those rules are called protocolsThose rules are called protocols

The first set of protocols was collectively called The first set of protocols was collectively called the Network Control Protocol (NCP)the Network Control Protocol (NCP)

ARPANET + PRNETARPANET + PRNET

In 1973 engineers start to look at the ways to In 1973 engineers start to look at the ways to connect ARPANET with packet radio network connect ARPANET with packet radio network (PRNET)(PRNET)

The idea was to establish a communication The idea was to establish a communication between system through radio waves.between system through radio waves.

It took almost 3 years to complete this It took almost 3 years to complete this

Satellite Network (SATNET)Satellite Network (SATNET) IN 1977 engineers joined the SATNET with the IN 1977 engineers joined the SATNET with the

other two netwok ARPANET & PRNET and other two netwok ARPANET & PRNET and collectively they termed it as collectively they termed it as inter-networking, inter-networking, or the Internetor the Internet

Other network like Other network like

USENET USENET

BITNET(Because It's There Network)BITNET(Because It's There Network)

CSNET(Computer Science Network)CSNET(Computer Science Network)

NSFNET(National Science Foundation Network) NSFNET(National Science Foundation Network) joins internet joins internet

Atlast in 1983, ARPANET switched to theAtlast in 1983, ARPANET switched to the

Transmission Control Protocol and Internet Transmission Control Protocol and Internet

Protocol suite (TCP/IP) from NCP, the same set Protocol suite (TCP/IP) from NCP, the same set

of rules the Internet follows todayof rules the Internet follows today

Several organizations and committees formed Several organizations and committees formed to shape the Internet to shape the Internet

They are They are

Internet Activities BoardInternet Activities Board

The Federal Research Internet Coordinating The Federal Research Internet Coordinating Committee Committee

The Federal Networking Council The Federal Networking Council

DevicesDevices

HUBHUB SwitchSwitch RoutersRouters

HUBHUBHubs are commonly used to connect segments ofHubs are commonly used to connect segments of

a LAN. It contains multiple ports.a LAN. It contains multiple ports.

What HUB does is, when a packet arrives at one What HUB does is, when a packet arrives at one

port, it broadcast the frame to the other portsport, it broadcast the frame to the other ports

Reason:Reason:

The hub has no way of distinguishing to whichThe hub has no way of distinguishing to which

port a frame should be sent to port a frame should be sent to

SwitchSwitchSwitch is a device that filters and forwards Switch is a device that filters and forwards

packets between LAN segmentspackets between LAN segments

Switches operate at the data link layer (layer 2)Switches operate at the data link layer (layer 2)

and sometimes the network layer (layer 3) of the and sometimes the network layer (layer 3) of the

OSI Reference ModelOSI Reference Model

With the help of MAC Address a Switch canWith the help of MAC Address a Switch can

identify which system is sitting on which port.identify which system is sitting on which port.

So when a frame is received, it forward that So when a frame is received, it forward that

frames to a respective(designated) port frames to a respective(designated) port

RouterRouter

A device that forwards data packets along A device that forwards data packets along

networks. A router is connected to at least two networks. A router is connected to at least two

Networks either two LAN or WANS or a LAN Networks either two LAN or WANS or a LAN

and it's ISP.and it's ISP.

Routers are located at gateways, the places Routers are located at gateways, the places

where two or more networks connect.where two or more networks connect.

Routers use headers and forwarding tables to Routers use headers and forwarding tables to

determine the best path for forwarding the determine the best path for forwarding the

packetspackets

Reference Reference

http://computer.howstuffworks.com/internet/basihttp://computer.howstuffworks.com/internet/basics/internet-start.htmcs/internet-start.htm

WikipediaWikipedia GoogleGoogle