Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Week 8: Networking and Telecommunication Basics

Communication Computer communications is the process of sharing data, programs, and information between two or more computersComputer communications is the process of sharing data, programs, and information between two or more computers Numerous applications depend on communication systems, includingNumerous applications depend on communication systems, including – –Instant messaging –Internet telephone –Electronic commerce

Communications Today Connectivity uses computer networks to link people and resourcesConnectivity uses computer networks to link people and resources The Wireless RevolutionThe Wireless Revolution –Single most dramatic change in connectivity and communications has been widespread use of mobile telephones with wireless Internet connectivity

Communication Systems Four basic elementsFour basic elements –Sending and receiving devices –Communication channel –Connection devices –Data transmission specifications

Communication Channels Communication channels carry the data from one computer to anotherCommunication channels carry the data from one computer to another Two categories of communication channelsTwo categories of communication channels –Physical connection Physical connectionPhysical connection –Wireless connection Wireless connectionWireless connection

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-6 McGraw-Hill Types of Transmission Media Guided Media :Guided Media : 1.Unshielded Twisted Pair (UTP) 2.Shielded Twisted Pair 3.Coaxial Cable 4.Optical Fibre Unguided Media :Unguided Media : 1.Radio Transmission 2.Microwave 3.Satellite Communication

Physical Connections Ethernet cableEthernet cable (Twisted pair cable) Coaxial cableCoaxial cable Fiber-optic cableFiber-optic cable Return

Wireless Connections Return Radio frequency (RF)Radio frequency (RF) –Bluetooth (short-range,10 Mtr) –Wi-Fi (wireless fidelity, 100 Mtr) –WiMax (1-5 KM) MicrowaveMicrowave SatelliteSatellite InfraredInfrared –Short distances and line of sight

Communication Channels Summary

Connection Device Signals Types of signalsTypes of signals –Analog –Digital

Connection Devices Types of modemsTypes of modems –Telephone modem –DSL (digital subscriber line) –Cable modem –Wireless modem (WWAN)

Networks A computer network is a communication system that connects two or more computersA computer network is a communication system that connects two or more computers Allows exchange of information and resourcesAllows exchange of information and resources

Computer Networks NodeNode ClientClient ServerServer Directory serverDirectory server HostHost SwitchSwitch Network interface cards (NIC)Network interface cards (NIC) Network operating systems (NOS)Network operating systems (NOS) Network administratorNetwork administrator

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-15 McGraw-Hill Types of netwoks local-area networks (LANs)local-area networks (LANs) wide-area networks (WANs)wide-area networks (WANs) campus-area networks (CANs)campus-area networks (CANs) metropolitan-area networks (MANs)metropolitan-area networks (MANs) home-area networks (HANs)home-area networks (HANs)

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-16 McGraw-Hill local-area networks (LANs) The computers are geographically close together (that is, in the same building).The computers are geographically close together (that is, in the same building).

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-17 McGraw-Hill wide-area networks (WANs) The computers are farther apart and are connected by telephone lines or radio waves.The computers are farther apart and are connected by telephone lines or radio waves.

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-18 McGraw-Hill campus-area networks (CANs) The computers are within a limited geographic area, such as a campus or military base.The computers are within a limited geographic area, such as a campus or military base.

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-19 McGraw-Hill metropolitan-area networks (MANs) A data network designed for a town or city.A data network designed for a town or city.

Copyright © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Computing Essentials 2012: Making IT Work for You 9-20 McGraw-Hill home-area networks (HANs) A network contained within a user's home that connects a person's digital devices.A network contained within a user's home that connects a person's digital devices.

LAN-MAN-WAN

Network Architecture Arrangement is called topologyArrangement is called topology Types of network topologyTypes of network topology –Legacy BusBusBus RingRingRing –Current StarStarStar TreeTreeTree HybridHybridHybrid MeshMeshMesh

Bus Network Each device is connected to a common cable, called a bus or backboneEach device is connected to a common cable, called a bus or backbone All communications travel along this busAll communications travel along this bus Return

Ring Network Each device is connected to two other devicesEach device is connected to two other devices No central file server or computerNo central file server or computer Useful in a decentralized environmentUseful in a decentralized environment Return

Star Network Most widely used network topology for both homes and large businessesMost widely used network topology for both homes and large businesses Each device connects directly to a central network switchEach device connects directly to a central network switch Return

Tree Network Each device is connected to a central node, either directly or through subordinate nodesEach device is connected to a central node, either directly or through subordinate nodes Also known as a hierarchical networkAlso known as a hierarchical network Return

Hybrid Network Combination of different topologiesCombination of different topologies Return

Mesh Network Does not use a specific physical layout, but requires that each node have more than one connection to other nodesDoes not use a specific physical layout, but requires that each node have more than one connection to other nodes Wireless technologies are frequently usedWireless technologies are frequently used Return

Network Topologies

Network Strategies Terminal server networkTerminal server network Client/server networkClient/server network Peer-to-peer (P2P) networkPeer-to-peer (P2P) network Distributed processing networkDistributed processing network Terminal ServerPeer-to-PeerClient/Server

Networking hardware Networking hardware typically refers to equipment facilitating the use of a computer network.Networking hardware typically refers to equipment facilitating the use of a computer network. Examples: bridge, hub, routers, switch, modem etc……

Bridge A bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments.A bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments.

HUB HUB - is a device for connecting multiple twisted pair or fiber optic Ethernet devices together and thus making them act as a single network segment.HUB - is a device for connecting multiple twisted pair or fiber optic Ethernet devices together and thus making them act as a single network segment.

Routers Routers are small physical devices that join multiple networks together.Routers are small physical devices that join multiple networks together.

Switch A network switch is a small hardware device that joins multiple computers together within one local area network (LAN).A network switch is a small hardware device that joins multiple computers together within one local area network (LAN).

Modem Definition : a combined device for modulation and demodulation, for example, between the digital data of a computer and the analogue signal of a telephone line.

Week 8 End