Network? Interconnected Collection ofautonomous Computers. Two computers are Interconnected Ifthey are capable of exchanginginformation. Computers on network can start,stop,or control another.
Need for Networking Resource Sharing Reliability Cost Factor Communication Medium
Application of Networks Sharing Access to remote data base Communication Facilities
Evolution of Networking ARPANET (Advanced Research ProjectAgency NETwork) It connected computers at differentUniversities and U.S. Defense. Another Federal Agency, the NationalScience Foundation, created a new, high-capacity network called NSFnet. NSFnet, more capable than ARPANET.
The Internet The Internet is a world wide network ofcomputer networks. Gateways and Backbone.
GatewayIt is a device that connects dissimilarnetworks. BackboneIt is central interconnecting structure thatconnects one or more networks just likespine of a human being.
Internet Functioning TCP/IP Transmission Control Protocol isresponsible for dividing and reassemblingmessage/file into packets on the sourcecomputer. Internet Protocol is responsible forhandling the address of destinationcomputer so that each packet is routed(sent) to its proper destination.
Server A computer that facilitates the sharingof data, software, and hardwareresources on the network, is termedas a server. Types:(i) Non-Dedicated Server(ii) Dedicated Server
Switching Techniques Switching techniques are used fortransmitting data across networks. Types:(i) Circuit Switching(ii) Message Switching(iii) Packet Switching
Transmission Media Connecting Media or ConnectingCables. Types: Twisted Pair Cable Co-axial Cable Optical Fibres
Type Sub TypeMaximum SegmentLength Bandwidth Installation cost InterferenceTwisted PairCable UTP 100 mts 100 mbps easy cheapest highSTP 100 mts 500 mbps moderate moderate moderateCoaxial Cable Thinnet 185 mts 10 mbps easy cheapest moderateThicknet 500 mts 10 mbps hard moderate lowFibre OpticCable Multinode 2 kms 100 mbps very hard expensive noneSinglenode 100 kms 2 gbps very hard expensive none
Types of NETWORKS Local Area Network (LAN) Diameter of network not more than a fewkilometer. Metropolitan Area Network (MAN) Diameter of network of about 100kilometers. Wide Area Network (WAN) Diameter of network more than 100’s ofkilometers.
Network Topologies Pattern of interconnection of nodes ina network is called the topology. Types: Star Bus Ring Tree Graph Mesh
Modem A computer peripheral that allows youto connect and communicate withother computers via telephone lines. Syncing Carrier wave with modulatingwave. Modulation and Demodulation Modulation types: AM (Amplitude modulation) FM (Frequency modulation) PM (Phase modulation)
Increasing Internet Speed Gauss Theorem states that “Surfaceintegral of electric field over a closedsurface is 1/ξ˳ times the chargeenclosed by it.” For a cylindrical surface:
i.e., ∫E.dS=q/ξ˳ As Information (I) is the charge per unit lengthand length of he wire is H, charge enclosed bysuface is:- ∫E.dS=IH/ξ˳ E(2ΠRH) (cos 0˚)=IH/ξ˳ I=Eξ˳(2ΠR) I is directly proportional to R, that is, doublethe radius of the wire double the informationpassed and so on.