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Mohamed Simad B - 49 1 Hardware and Networking Hardware The physical component of a computer is known as hardware. Internal hardware devices • Mother board • Processor • RAM & ROM • Hard disk Scanner Speaker Key board Screen Headphone / Microphone Joy stick Mouse Printer Web cam System Unit / Cabinet Mohamed Simad B - 49 2 • SMPS (switch mode power supply) • CD/DVD drive • AGP card • NIC card • Sound card External hardware devises • Key board • Mouse • Monitor • Scanner • Printer • Webcam • Headphone & Microphone • Joy stick • Speaker Q. List out any 10 input devises and 5 output devises. Input devises 1. Key board 2. Mouse 3. Scanner

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Mohamed Simad B - 491

Hardware and NetworkingHardwareThe physical component of a computer is known as hardware.Internal hardware devices• Mother board• Processor• RAM & ROM• Hard diskScannerSpeakerKey boardScreenHeadphone / MicrophoneJoy stickMousePrinterWeb camSystem Unit / CabinetMohamed Simad B - 492• SMPS (switch mode power supply)• CD/DVD drive• AGP card• NIC card• Sound cardExternal hardware devises• Key board• Mouse• Monitor• Scanner• Printer• Webcam• Headphone & Microphone• Joy stick• Speaker

Q. List out any 10 input devises and 5 output devises.Input devises1. Key board2. Mouse3. Scanner4. Microphone5. Joy stick6. Track ball7. Light pen8. Touch screen

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9. Web came10. Bar code readerOutput devises1. Printer2. Monitor3. Speaker4. Projector5. Head phone6. PlotterMohamed Simad B - 493Network Topologies1. What is Topologies?Topology is the shape of the network.2. What are the types of Topologies?• Bus Topology• Star Topology• Ring Topology• Mesh Topology• Hybrid Topology3. What is the first topology?Bus topology4. What is the most common topology now?Star topologyBus Topology• All the computer (servers, client computers) and other networking devices (Printers) areconnected in a linear Backbone Cable.Client 1 Client 3Client 2 ServerPrinterTerminator Terminator‘T’ connectorBackbone cable (Coaxialcable)Mohamed Simad B - 494• Both end of the back bone cable is terminated by the terminators.• All the computers are connected with a backbone cable by using ‘T’ connectors.• The terminators at the both ends prevent the data from data loss and prevent the data signalsto bounce back.Advantages of Bus topology• It is very cost effective (cheap to implement• No need of switch and hubsDisadvantages of Bus topology• Scalability is very less• If there is any problem in the backbone cable or connectors, the entire network will fail.• It is suitable only for small network.Star Topology

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Client 5Client 1 Client 2File serverClient 3Client 4Database serverPrinterSwitchMohamed Simad B - 495• All the components and other networking devices are connected with the centralized hub orswitch.• Star topology is one of the most common computer network topology today.Advantages of star Topology• Scalability is very high.• Better performance.• Isolation of devices.• SimplicityDisadvantages of star Topology• The primary disadvantage of star Topology is the high dependence of the centralized hub orswitch.• If the centralized hub or switch fails due to power failure or hardware failure the entire networkwill fail.Ring TopologyClient 3Client 4 Client 2Client 1Mohamed Simad B - 496• Computers are connected in a ring like fashion.• Each nod connected to exactly two other nodes forming a single continues pathway for signalsto travel through each node.• Data travels from node to node.• It works based on token – Ring standards.• Data flow in unidirectional in ring topology.• Token contains the data, source MAC address and Destination MAC address.Advantages• No data collision – Because data flow is unidirectional• Every computer acts as a repeater, it regenerates the signals (tokens) on its own.• Does not require network server to manage the connectivity between computers.• Performs better than a star topology under heavy network load.RingClient 3Client 1Client 2Client 4Mohamed Simad B - 497

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• Every device has access to the token and the opportunity to transmit.Disadvantages• If any one of the node fails or any problem in the cable can create problems for the entirenetwork.• Slower than an Ethernet network.• Network cards are expensive than Ethernet network cards.• Moves, adds and charges of devices can affect the entire network.Mesh Topology:• All the computers are interconnected with every other computer in mesh topology.• Dedicated connection.Node 1 Node 2Node 3 Node 4Mohamed Simad B - 498Advantages:• High fault tolerance• Mesh network is very reliable.• Mesh topology is suitable for wireless networks.Disadvantages:• It requires more cable segments and more network adaptors.• It is highly impractical in wired networks.Hybrid Topology• It is the combination of two network topologies.• The resulting network does not exhibit one of the standard topologies (e.g. Star, Ring, etc.)Example: Star + Bus network = Hybrid topology.SWITCH

STAR 1Terminator TerminatorSWITCH

STAR 2BUSServerT-Connector

Mohamed Simad B - 499Client 1 Client 2ServerTerminator‘T’ connectorBackbone cable (Coaxialcable)Client 3File serverClient 5Client 4Database serverSwitchClient 6Client 7SwitchMohamed Simad B - 49

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10Types of networks:1. LAN2. MAN3. WAN4. PANLAN (Local Area Network):Distance Limit: 0 – 2kms• Interconnection of computers (Server/Clients) and other networking devices (Printer, FaxMachines, IP Telephone, Scanner, Router, etc.,) for the purpose of file sharing and resourcessharing with a small geographical area such asw Network within an office buildingw Networks between two office building (near <2kms)w Networks at schools, colleges, universitiesw Networks at hospitals, shops.PrinterFile serverClient 3Client 2SwitchClient 1Mohamed Simad B - 4911MAN (Metropolitan Area Network):• Distance Limit: 2 – 50kms• Interconnection of computers (Server/Clients) and other networking devices (Printer, FaxMachines, IP Telephone, Scanner, Router, etc.,) for the purpose of file sharing and resourcessharing between two buildings within the same metropolitan city or between two metro cities(not greater than 50kms).ServerSWITCHClient 1 Client 2 Client 3 ClientPrinter ServerSWITCHClient 1 Client 2 Client 3 ClientPrinterLAN 1 at Male’ LAN 2 at VillingiliRouter RouterPrinterFile serverClient 3Client 2HubClient 1PowerMohamed Simad B - 4912Protocol• Protocol is set of rules that govern the information or data flow between computer within thenetwork and between computer networks.

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• There are number of protocols exist in computer networks.SL – No Protocol Port number Uses1 HTTP(Hyper Text Transfer Protocol()80 Unsecured web browsing.2 HTTPS(Hyper Text Transfer ProtocolSecured)443 Secured web browsing.3 FTP(File Transfer Protocol)20 – Data21 – ControlTo download or upload files to and from thefile server. (file transfer)4 SMTP(Simple Mail Transfer Protocol)25 Outgoing mail – To send mail from yourcomputer.5 POP3(Post Office Protocol version 3)110 Incoming mails – to receive mails.6 DNS(Domain Name System)53 To convert domain names in to Ip addressesand Ip address into domain name.7 DHCP(Dynamic Host ConfigurationProtocol)67 – Server68 - ClientsTo assign Ip address dynamically to all clientcomputers in a network8 Telnet(Telephone Network) 23 Text Based protocolRemote administratonHub• A hub is a small electronic devices, that joins multiple computers and other networking devicessuch as printers, routers, modems, together within a local area networking (LAN).• A hub is common connection point for networking devices in a network.• Hub receives signals from one device and broadcasts it to all other devices in the network.Mohamed Simad B - 4913Types of Hub1. Active Hub2. Passive HubPassive Hub• A passive hub passes signals along (or) broadcasts signals but has no addition capability ie, itdoesn’t contain amplifier to regenerate the signals.• It doesn’t require external power supplyActive Hub• An active hub is a hub that includes a signal amplifier. It regenerate or amplifies signals and

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passes them along.• It requires external power supply.Active hub = Hub + repeaterPrinterFile serverClient 3Client 2HubClient 1PowerMohamed Simad B - 4914Switch• Switch is a common connection point in a network to connect multiple computers and othernetworking devices together.• It join multiple connectors and other networking devices within one local area network (LAN)• Switch works at data link layer (layer 2) of the OSI model• Switch are capable of inspecting data packets determining the source and destination devices ofthe packet and forwarding it appropriately.Types of switch1. Unmanaged switch2. Managed switchUnmanaged switch• There is no configuration interface in unmanaged switches• We can configure unmanaged switch• We can’t create VLANPrinterFile serverClient 3Client 2SwitchClient 1Mohamed Simad B - 4915Difference between hub and switchHub SwitchHub works in the physical layer of the OSI model; itis a layer 1 device.Switch works in the data link layer of the OSImodel; It is a layer 2 device.Hub always broadcasts data packets Switch broadcasts data packets for the first time,second time own wards it unicasts data packets.Hub shoes the band width Switch doesn’t share the band widthHub doesn’t understand the MAC address Switch can understand the MAC addressHub doesn’t maintains the MAC table Switch maintains the MAC tableNetwork traffic and data collision is high Network traffic and data collision is very lessDifferences between switch and routerRouter Switch

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Router is used to connect two different networks Switch connects different computers within onenetwork.Router works in the network layer of the OSImodel, It is a layer 3 devices.Switch works in the data link layer of the OSImodel. It is a layer model.A router works on the principal of IP address A switch work on the principal of MAC address.Routers have their own in built operating systemand they need to be configured before used.Most of the switches do not require any priorconfiguration and are usually ready to use.Routers are much more sophisticated andintelligent network device as compared toswitches.In comparison with router switches are lesssophisticated and less intelligent.A routers inbuilt hardware and software makesuse of routing algorithms to compute the bestpossible path for routing data packets acrossdifferent computer networks.A switch does not perform any such activity.Different between FAT and NTFSFAT NTFSFile Allocation Table New Technology File SystemFAT volume can be converted to NTFS volume NTFS cannot be converted to FAT32 volumeFAT does not support file compression NTFS support file compression & encryptionFAT provides very little security. It support sharelevel security only. It doesn’t support file level andfolder level security.NTFS provide high level security it supports sharelevel, file level and folder level security.FAT volume are recognized by all versions ofwindows O/S starting from win-98 up to win -7NTFS volume are not recognized by windows95/98/ME (Lower version of windows)Mohamed Simad B - 4916Operating SystemCommon diagram for OS• Operating system is system software.• It acts as an interface between the user and the computer hardware.• Operating system provides an environment at which we can install all the applications.• Without OS we can’t boot the computer, we can’t operate the computer.• Operating system controls and manages the entire activities and resources of a computer.4 users3 Application software (CorelDraw,Photoshop)2 Operating system (XP,

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win951 ComputerhardwareMohamed Simad B - 4917Over a certain period of time computer starts functioning slowlyTroubleshooting steps• Execute disk clean up tools to delete unnecessary files.• Execute disk defragment tool to consolidate the fragmented files across the hard disk.• Uninstall the unwanted, unnecessary application program from your computer.• Managing your program and cleaning your registry can easily boost your computersperformance speed up to 30% ( Registry-cleaner software)• Increase virtual memory• Scan the entire hard disk drive for viruses and other threats.• Disable unnecessary startup items and programs in MS config.Differences between RAM and ROMRAM ROM1-Random Access memory 1-Read only memory2-Read and write operation is possible 2-Only read operation is possible / write is notpossible3-User can interact with RAM 3-User can’t interact with ROM4-Volatile Memory 4-Non-volatile5-RAM is temporary memory 5-ROM is permanent memoryComputer Power Supplyè The computer’s components would not be able to operate without powerè The device in the computer that provides this power is the switch mode power supply (SMPS)è SMPS converts 110 volt to 230 volt AC current into the various DC voltages that a computer needs tooperate.è Various DC voltages we can get from an SMPSo +3.3 Volt DCo +5 Volt DCo -5 Volt DC - groundo +12 Volt DCo -12 Volt DC -groundo +5 Volt DC -standbyATX AT Motherboard MotherboardMohamed SimadPower supply connectorsè SMPS use 4 types of power connectors to power the various devices within computer1- Floppy drive power connector2- AT(Advanced Technology) system power connector3- ATX(Advanced Technology Extended) system power connector4- Standard Peripheral power connectorsè Each has a different appearance and way of connecting to the device. Each type is used for a specificpurpose.1. Floppy drive power connector- Floppy drive pc is smaller and flatter These connectors also called as “berg connector

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- There are 4 wires going to the connector. These wires carry the 2 voltages used by the motorsand logic circuits.o +5 V DC – carried on the red wireo +12 V DC – carried on the yellow wirePlus 2 black ground wires- Color Coding2. Standard Peripheral Power Connector- The standard peripheral power connector is generally used to power different types of internaldisk drives – Hard disk, CD Drive, DVD- This type of connector is called a “Molex connector”- This power connector, though lacode scheme as the floppy drive connector.-3. AT System Power Connectors: Dual Power Connector- There are two 6 wire connectors, labeled p8 and p9.18eripheral DVD-Drive except floppy drive.larger than the floppy drive connector, uses the same wiring colorB - 49connectors”rgerMohamed Simad4. ATX Power Connector- ATX Power connector provides power supply to ATX motherboard- It provides the six voltages required plus it delivers then all through one connector a single 20pin connectorNetwork interface card• NIC connect a computer and other networking devices with a network• Without NIC card a computer cannot participate in a network.Two types of NICs:• Wireless NIC• Wired NIC• Now a day NIC is in built in the mother board.• Interface is the place where data arrives or departs from a computer.Name of port• NIC has got 1 RJ-45 port to conneASCII (America Standard Code for In• ASCII is code for representing English character (alphabet) and special symbols as numbers,with each letter assigned number from 0 to 127.• Most computer use ASCII codone computer to another.• ASCII developed from telegraphic codes.• ASCII was developed under the auspices of committee of the American Standards Association,called the X3 committee.Unicode19vides connect a computer with a network.Information Interchange)

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codes to represent text, which makes it possible to transfer data fromB - 49esMohamed Simad B - 4920• Unicode provides a unique number for every chapter, no matter what the O/S, no matter whatthe program, no matter what the language.• The Unicode standard has been adopted by such industry leaders Apple, HP, IBM, Microsoft,Oracle, SAP, Sun, Sybase, Unisys character set.• Microsoft software uses Unicode at its core.• Major operating system windows, Macintosh, Linux, Unix, support Unicode.EBCIDIC (Extended Binary Coded Decimal Interchange Code)• Extended Binary Coded Decimal interchange Code• EBCIDIC is an IBM code for representing character as numbers. Although it is widely used onlarge IBM computers, most other computers include PCs and Macintosh use ASCII codes.Difference between FTP and TFTPFTP - File Transfer ProtocolTFTP - Trivial File Transfer Protocol• We use both FTP and TFTP protocol in a computer network to transfer file in between thecomputersFTP TFTPFTP uses TCP protocol TFTP uses UDP protocolFTP needs secure user name and password TFTP doesn’t require secure username andpasswordSecured protocol Unsecured protocolFTP more commands TFTP less commandsFTP reliable but slower than TFTP TFTP unreliable but faster than FTPFTP uses TCP ports 20 & 21 TFTP uses UDP port 69Mohamed Simad B - 4921Motherboard layoutPorts and Slots on the motherboard1- Keyboard Connector – to connect keyboard2- Mouse Connector – to connect mouse3- Serial Port – to connect serial printer, modem4- Parallel Port - to connect parallel printer5- USB Ports – to connect USB devices – Printer, Webcam, Scanner etc6- VGA Port – to connect monitor , projector7- Network Port (RJ45) – to connect network cable8- Game Port – to connect joystick9- Audio Ports – to connect external speakers, microphone, headphone10- PCI Slots – to connect NIC card, Sound Card, VGA Card, MIDI card etc.11- Memory Slots – to connect DIMM memory modules12- Power Connector – to connect SMPS 20pin power connectorKey board connectorMouse connectorSerial portParallel portUSB port

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VGA portNetwork portGame portLine inLine outMicrophonePCI portsPS2 portsNorth BridgeChipsetChassis cooling fan connectorBIOS memory chipMother board power connectorFloppy drive connectorIDE portsIDE1 IDE0Graphics (AGP port)CMOS batteryInbuilt speakerProcessor slotProcessor fanconnectorDIM memorymodulesSouth Bridge Chipset

Mohamed Simad13- AGP Port – to connect graphics card14- IDE Ports – to connect disk storage devices (Hard disk, CD/DVD drive)3 types of Internet Connection1. Dial-up:• The internet connection that is established by using telephones and telephone lines as amedium is known as dialup internet connection.• Telephone remains busy while ac• A modem is used to connect the computer to the ISP. Once the connection is established anactivity called “handshaking” takes place between the modem and the remote server.• The dialup internet connection is also known as ‘transientconnection can be terminated by either the ISP or the other user• Dialup connection supports up to 56kbps bandwidth.2. Broadband:• If any internet connection that support 512kbps or higher bandwidth will be considered asbroadband internet connection.• Broadband means a wide range of frequencies used to transmit and receive data.• In broadband IC, the data transfer rates are very high as compared to the dialup internetconnection.• We can use telephone while accessing the int22sk accessing the internetconnection’. This is because theinternet.B - 49Mohamed Simad B - 4923• There are various types of broadband internet connections, depending upon the cost , speedand availability.1. ADSL

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2. SDSL3. Wireless broadband4. Cable broadband5. Satellite broadband6. Fiber optic broadband3. Cable Internet Connection:• Internet can be accessed via the cable TV connection• The cable TV is used by almost everybody and now the internet connection is also madeavailable along with the cable TV channels.• Cable broadband Internet connection provides a speed ranging from 2mbps to 10 mbps• It is more poplar compared to the ADSL internet connection• The downloading and uploading speeds of cable & ADSL are the sameMohamed Simad B - 4924OSI – Reference modelOSI – Open System Inter Connection• OSI model was designed by ISO – International Standard Organization.• OSI model is logical model; it is not a physical model.• There are seven virtual layers in OSI model each layer performs a well defined function.• Without OSI (or) TCP/IP model data communication is not possible between computer in a localarea network as well as in the internet.Router atsourceSender PCat indiaApplication LayerPresentation LayerSession LayerTransport LayerNetwork LayerData Link LayerPhysical LayerReceiver PCat USAApplication LayerPresentation LayerSession LayerTransport LayerNetwork LayerData Link LayerPhysical Layer Physical LayerData Link LayerNetwork LayerISP ISPRouter atDestination0101010011010110101

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Physical LayerData Link LayerNetwork Layer0101010011010110101Mohamed Simad B - 49251. Application LayerThis layer is point of contact between the user and the network therefore; it brings the basicnetwork service to the user, such as file transfer, email, remote login.• Protocols: HTTP, HTTPS, FTP, SMTP, Telnet, Pop32. Presentation LayerThis layer deals with the syntax and semantics of the transmitted data, it processes the data soas to make it compatible between communicating tasks. This layers can covert, format, encryptand compress the data3. Session LayerThis layer sets up and synchronizes the exchange between distant processes. It binds logicaladdresses for distributable tasks.4. Transport Layer• The layer is responsible for the good/reliable delivery of messages to the recipient /destination. Its main road is to take the messages of the session layer, split them in tosmaller units (segments) and give them to the network layer.• This layer can use one network connection to transport several messages at the same timeusing multiplexing unit.• This layer is also responsible for flow control. The information unit for this layer is themessage or segment.• Protocols in Transport layer(TCP/UDP)5. Network Layer• This layer is in charge of sub network ie. The routing packets over the subnet work and theinter connection on the various sub networks.• The information unit for this layer is the ip packets.• Protocols of the network layer: IP, IPSEP, ICMP, IGMP, RIP, IGRP, EGRP, OSPF.Transport LayerNetwork LayerData Link LayerSegment 1 Segment 2 Segment 3 Segment 4 Segment 5

IP IP IP IP IP IP IPMac Mac Mac Mac Mac Mac MacIP PacketsMac address

010011010101110011110101010101010110110101011001Mohamed Simad B - 49266. Data Link Layer• It has a role of binder, it splits input data of the sender in to frames since this frames insequence and manages the acknowledgment frames send back by the receiver.• An important role of this layer consists in detecting and correcting errors that occurs in thephysical error.• This layer integrates also a flow control function to avoid the blocking of the receiver.• The information unit of this layer is data frame.

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• Protocol: PPTP, L2TP, MAC, ARP, RARP.7. Physical Layer• This layer is in charge of the transmission of bits over a communication channel.• This layer must guarantee perfect transmission of the data.• The information of this layer is the binary bits.• Devices at physical layer: Physical layer has no additional functionality, but it depend ondata link layer for all the function• Devices working at physical layer: Hub, repeater, Cable, connector such as RJ11, RJ45,Ethernet, token ring, ATM, Frame riley.TCP / IP model1. Application Layer• This layer is point of contact between the user and the network therefore; it brings the basicnetwork service to the user, such as file transfer, email, remote login.Physical LayerBinary Bits

Application LayerTransport LayerInternet LayerHost - to – Networklayer (or) link layer 1234

Mohamed Simad B - 4927• This layer is immediately bound to the transport layer simply because the session andpresentation layers in TCP/IP model are useless.• Protocols: HTTP, HTTPS, FTP, SMTP, Telnet, Pop32. Transport Layer• The layer is responsible for the good/reliable delivery of messages to the recipient /destination. Its main road is to take the messages of the session layer, split them in tosmaller units (segments) and give them to the network layer.• This layer can use one network connection to transport several messages at the same timeusing multiplexing unit.• This layer is also responsible for flow control. The information unit for this layer is themessage or segment.• Protocols in Transport layer(TCP/UDP)• It has the same role as the transport layer of the original model.• Its role is to split up the message to be transmitted into a form the internet layer canhandle.3. Internet layer• This layer is in charge of sub network ie. The routing packets over the subnet work and theinter connection on the various sub networks.• The information unit for this layer is the ip packets.• Protocols of the network layer: IP, IPSEP, ICMP, IGMP, RIP, IGRP, EGRP, OSPF.• This layer is responsible for the inter connection of the remote networks withoutestablishing a physical connection. Its role is to inject packets in to any network anddeliver to the destination independently to one another.4. Host- to – network layer

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• This layer seems to cover both physical and data link layer of the OSI model.• This layer has not been really specified the only constrain of this layer is to allow a host tosend a IP packets of a network.• There is no protocols• Devices working at physical layer: Hub, repeater, Cable, connector such as RJ11, RJ45,Ethernet, token ring, ATM, Frame riley.Mohamed Simad B - 4928Packet format• A TCP packets resides within IP packet• An IP packet resides within an Ethernet packet• A HTTP packets resides within a TCP – packetTCP Packet• TCP packet contains only port numbers not the IP address or MAC addressIP Packet• IP packet contain only IP addresses not the MAC addressEthernet frame packetSender port number Receiver port number DataSender IP address Receiver IP address DataTransport LayerNetwork LayerData Link LayerSegment – TCP packetPacket – IP packetFrames – Ethernet framesApplication LayerPresentation LayerSession LayerRaw data – HTTP packetMohamed Simad B - 4929• Ethernet frames packet contains only MAC address not the IP address.Compare and contrast OSI model with TCP/IP modelSimilarities:• They share similar architecture both of them are constructed with layers• They share a common application layer• Both models have comparable transport and network layers• Both models assume that packets are switched; basically this means that individual packets maytake different path in order to reach the same destination.DifferencesOSI reference model TCP/IP reference modelDefined before advent of internet Defined after advent of internetOSI model came into existence way before TCP/IPmodel was createdTCP / IP model came into existence after OSImodelISO created OSI model DARPA created TCP / IP modelService, interface and protocols are clearly

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distinguishedService, interface and protocols are not clearlydistinguishedInter- networking not supported TCP / IP support internetworkingStrict layering Loosely layeredLess credible 8 7 layers Less credible 8 4 layersCross over cableDTE (data terminal equipment): PC, RouterDCE (data communication equipment): Switch, modemSimilar devicesCross over cableDissimilar devicesStraight through cableSender MAC address Receiver MAC address DataPC PCPC switchMohamed Simad B - 4930Configuration cableRoll over cableWireless communication Techniques• Wireless communication is the transfer of information over a distance without the use ofelectrical conductors or wires.The distance involved may be1. Short distance WC – a few meters as in Television remote control.2. Long distance WC – thousands or millions of kilometers for radio communications (Radio, TV,broadcasting )Example of Wireless communication devices1. Mobile phone (or) cellular phones2. Cordless telephones3. PDA (Personal Digital Assistant)4. Wireless computer networking5. Wireless mouse and keyboard6. TV remote control7. Satellite TV & RadioAdvantages of Wireless network• Wireless communications permit services such as long distance communications, which areimpossible or impractical to implement with the use of wires.• It covers greater distance.• No need of cables and connectors.Source Pc Destination PCWireless NIC Wireless NICWirelessRouter orWAPMohamed Simad B - 4931Energy we use to transfer data wirelessly.

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• Radio frequency (RF)• Infra red light or wave• Laser light• Visible light• Sound energy• Microwaves (or) electromagnetic waveBluetooth• Bluetooth is an open wireless protocol for exchanging data over short distance (using shortlength radio waves) from fixed and mobile devices.• Bluetooth is a standard and a communication protocol primarily designed for low powerconsumption, with a short range based on low – cost transceiver microchips in each devices.• Bluetooth makes it possible for these devices to communicate each other when they are inrange, because the devices use radio waves, they do not have to be in line of sight of each other.Infrared• Infrared radiation is electromagnetic radiation with the wave length between 07 and 300 micrometers, which equates to a frequency range between approximately 1 and 400 htz.• Its wave length is longer when the frequency is lower• Its wave length is Shorter when the frequency is higher• Shorter§ Shorter infrared waves are not hot at all in fact you cannot even feel them. Theseshorter wave lengths are the ones used by your TV’s remote control.§ Far infrared waves: we experience this type of infrared radiation everyday in the form ofheat.§ The heat that we feel from sunlight, a fire, a radiator is infrared.Wireless Fidelity (Wi-Fi)§ Wi-Fi is a wireless LAN technology that enables laptops, PDAs, and other devices to connecteasily to the internet.§ Wi-Fi is sometimes called “Wireless Ethernet”§ Wi-Fi is less expensive and nearing he speeds of standard Ethernet and other common wirebasedLAN technologies.§ Wi-Fi uses the same radio frequencies as Bluetooth but with higher power, resulting a strongerconnection.§ Wi-Fi enables a faster connection, better ranges from the base station , and better security thanBluetooth.Mohamed Simad B - 4932Difference between plug & play and Non plug & Play.Plug and Play Non Plug and Play1-No need to install device driver software, it willautomatically install device driver andautomatically configure the device settings1-We must install device driver software for allnon plug and play devices manually2-After connecting the device, it is ready to use 2-After connecting the device we can’t use thedevice until we install device driver3-Pendrives, Hard disks(Internal, External)CD,DVD Drives, USB Keyboard, Mouse etc3-Printers, Scanners, Web Cam, Plotter, NIC Card,

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Sound Card, AGP Card etc.Hot Swapping• The ability to add and remove devices to a computer while the computer is running and have theoperating system automatically recognize the change• Two external bus standards1- Universal Serial Bus (USB)2- IEEE 1394 – Support hot pluggingDifferences between World Wide Web (WWW) and the Internet1- The World Wide Web (www) or simply the web is global information medium. Users can read andwrite via computers connected to the internet.2- The term is often mistakenly as a synonym for the internet itself, but the web is a service thatoperates over the internet, as e-mail does -> the World Wide Web is a system of interlinked hypertext documents accessed via the internet.3- The world wide web was invented in 1989 by the English physicist Tim Berners – LeeWorld Wide Web Internet1-Global Information medium 1-Global Network2-www is a service that operates over theinternet2-Internet is not a service3-www was invented in 1989 by the Englishphysicist Tim Berners - Lee3-ARPNET was the first internet, invented byARPA.How can we protect small office or home office or computer network?1- Install or implement basic hardware firewall at the gateway2- Install Antivirus software (AVG, McAfee, E-scan, Symantec etc)3- Use username & password for all user accounts4- Assign Static IP Address to all client computers5- When using a wireless connection, use the strongest security technique such as WPA or WPA26- Install a fairly strong hardware firewallMohamed Simad B - 49337- Install a proxy server to keep unwanted people out.8- Install antivirus server and update it regularly.9- For authentication, use strong password and change it on weekly base.Various Memory1. Cache memory2. Virtual memory3. Secondary memory4. Main memoryMain Memory• Main memory is also known as internal memory, Primary memory, memory.• Internal storage area in the computer, the term memory indentifies data storage that comes inform of chips and the word storage is used for memory that exists on disk or tapes.• Main memory has arrays of boxes each of which can hold a single byte of information.ROM RAMROM SRAMPROM DRAM

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EPROM SDRAMEEPROM RDRAMDDR IDDR IIDDR IIICharacteristics of Main Memory• Main memory is volatile memory• CPU can directly access main memory (RAM)• Storage capacity of main memory is very less compared to secondary storage devices.Secondary memory (or) storageCharacteristics of Secondary memory (or) storage• Secondary storage devices are non volatile memory• Permanent memory• CPU access secondary storage devices through input / Output channels.• Storage capacity is huge compared to main memory.Mohamed Simad B - 4934• Secondary storage devices are used to store huge amount of data permanently for future use.• Data is kept for a longer time on secondary storage devices.• Secondary storage does not loss the data when the device is power down.• Eg. Internal Hard Disk, External Hard Disk, CD/DVD, Floppy Disk, Magnetic Tape, Pen DriveVirtual MemoryVirtual memory is a computer system technique which use an application program the impression that ithas contagious working memory. While in fact it may be physically fragmented and may even overflower on to disk storage.Cache memory• Cache memory is the smallest memory among all.• Cache memory is the fastest memory among all. (Speed of cache memory is the equal to thespeed of processor.)• CPU contains cache memory.• A cache memory is used by the processor (CPU) to reduce the average time to access the mainmemory (RAM)800 MB 512 MBRAM800MB 9.7 GBProgram SizeMain memory300MBHard disk512 + 300 = 812 MBProcessor CachememoryMainmemoryMohamed Simad B - 49351000 times faster than Main memory SRAM DRAMWINS & DNS

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WINS –Windows Internet Name ServiceDNS –Domain Name Service• WINS & DNS are both name resolution service for TCP / IP networks.• Environments that include some computers that use NetBIOS names (win-98, Win-NT, Win-me)and other computers that use domain names (win-XP, vista, 7, 2000, 2003, 2008) most includeboth wins and DNS servers.• The server which provides wins services to the client computers is called as wins server.• The server which provides DNS services to t he client computers is known as DNS servers.• If you are using NetBIOS over TCP / IP you will need to have Wins server running so that eachcomputer can find the correct IP address of the other to communicate.• If you are using Domain names over TCP / IP you will need to have DNS server running so thateach computer can find the correct IP address of the other to communicate.What is an IP address?• An IP address is a unique numeric identifier for a host, printer, router, modem, placed innetwork.• An IP address (internet Protocol address) will allow the host to communicate with other host ina network.• Networking devices will be assigned IP addresses in order to identify and communicate witheach other in a network utilizing the internet protocol.• Any participating network device including routers, switches, client and server computers,network printers, internet fax machines, modems, and some IP telephones can have it own IPaddress that is unique within the scope of the specific network.• IP addresses are created and managed by the Internet Assigned Numbers Authorities (IANA).• If IP address is not assigned to a computer that particular device cannot participate in thenetwork.Classification of IP addresses Type of IP addressPrivate IP address IP V4 32bitsPublic IP address IP V6 128bitsMohamed Simad B - 4936Private IP Public IP1. Non routable IP address 1. Routable IP address2. Un-Registered IP address 2. Registered IP address in the internet3. No need to pay for private IP address 3. Need to pay for public IP address4. Intranet purposes 4. Internet PurposesPrivate IP address rangesClass A:10.0.0.0 to 10.255.255.255Network part 8 |Host part 24Subnet mask: 255.0.0.0Class B:172.16.0.0 to 172.31.255.255Network part 16|Host part 16Subnet mask: 255.255.0.0Class C:192.168.0.0 to 192.168.255.255Network part 24|Host part 8Subnet mask: 255.255.255.0

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Public IP address range Full FormClass A: 1-1268/24Subnet mask:255.0.0.01.0.0.0 to 126.255..255.255Class B: 128-19116/16Subnet mask:255.255.0.0128.0.0.0 to 191.255.255.255Class C: 192-223 192.0.0.0 to 223.255.255.255Mohamed Simad B - 493724/8Subnet mask:255.255.255.0Class D: 224-239(not defined)Subnet mask: (not defined)224.0.0.0 to 239.255.255.255Class E: 240-255(not defined)Subnet mask: (not defined)240.0.0.0 to 255.255.255.255Special Purposes IP addresses1. 0.0.0.0 to 0.255.255.255 default network address2. 127.0.0.0 to 127.255.255.255 Loopback IP address3. 255.0.0.0 to 255.255.255.255 Limited IP address4. Class D: Multicast5. Class E: Reserved for future use (or) research & developmentTypes of IP addressesIPV4 IPV632 bits 128 bits192.168.1.1 A6C2:884F:C849:f 864:AC29:C375:Df1E (0-9,A-F)We use classes in IPV4 class A,B,C,D,E No classes in IPV4It supports unicast broadcast and multicast It support unicast, multicast and anycast it doesn’tsupport broadcast.0.0.0.0127.0.0.0 Special purpose IP address255.255.255.2550:0:0:0:0:0:0:0 - protocol implementation.0:0:0:0:0:0:0:1 - loop back IP address.IPaddressclassTotal # of bitsfor networkingid / Host idFirst octectof IP address

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# OfnetworkID bitsused toidentifyclassUsable # ofnetworkingID bitsNumber ofpossiblenetwork# Of host IDper NetworkIDClass A 8/24 0XXX XXXX 1 8-1=7 27 -2=126 224-2=16,777,24Class B 16/16 10XX XXXX 2 16-2=14 214=16384 216-2=65,534Class C 24/8 110X XXXX 3 24-3=3 221=2,097,152 28-2=254