2 Network Definition Set of technologies that connects computers Allows communication and collaboration between users
3 The Uses of a Network Simultaneous access to data Data files are sharedAccess can be limitedShared files stored on a serverSoftware can be sharedSite licensesNetwork versionsApplication serversTeaching TipFigure 9A.2 on page 342 visually describes the sharing process. It can be helpful to have students open a shared file that you control. Make a change then have the students open it again. Alternatively, share a document and allow your students to write in it. Then demonstrate how the shared document changes.Spend time discussing why application servers need to be so powerful.
4 The Uses of a Network Shared peripheral device Printers and faxes are common sharesReduces the cost per userDevices can be connected to the networkPrint servers control network printingManage the print queueTeaching tipFigure 9A.4 on page 344 shows a print queue. It can be helpful to demonstrate your classroom queue.
5 Sharing DataFile server contains documents used by other computers.
6 The Uses of a Network Personal communication Email Conferencing Instantaneous communicationConferencingTele conferencingVideoconferencingAudio-conferencingData-conferencingVoice over IPPhone communication over network wiresTeaching tipIt is fun if you can setup a teleconference in your classroom. Students get to learn how to join or create the conference. Additionally, they learn how to participate. Finally, students have fun, especially with shared whiteboards.
8 Common Network Types Local Area Network (LAN) Contains printers, servers and computersSystems are close to each otherContained in one office or buildingOrganizations often have several LANSTeaching tipUse a real world example to describe an organization with interconnected LANs.
9 Common Network Types Wide Area Networks (WAN) Two or more LANs connectedOver a large geographic areaTypically use public or leased linesPhone linesSatelliteThe Internet is a WANTeaching tipBlockbuster Video uses a WAN to connect it’s stores nationwide. Customers from Pittsburgh may rent videos in Hilton Head. Late fees will even be displayed!
10 Hybrid Network Types Campus Area Networks (CAN) A LAN in one large geographic areaResources related to the same organizationEach department shares the LAN
11 Hybrid Network Types Metropolitan Area Network (MAN) Large network that connects different organizationsShares regional resourcesTeaching tipAn example of a regional resource is a supercomputer. For example, Pittsburgh has the Pittsburgh Super Computing center ( The various colleges in Pittsburgh connect to the center through a MAN in Pittsburgh.
12 Hybrid Network Types Home Area Network (HAN) Small scale network Connects computers and entertainment appliancesFound mainly in the home
13 Hybrid Network Types Personal Area Network (PAN) Very small scale networkRange is less than 2 metersCell phones, PDAs, MP3 playersInsider informationPAN is very new. Few devices support PAN. High end cell phones include Bluetooth technology. Once the technology matures, Bluetooth will allow the creation of a PAN.
14 How Networks Are Structured Server based networkNode is any network deviceServers control what the node accessesUsers gain access by logging inServer is the most important computerTeaching tipSpend a few minutes here discussing password policies. Describe why it is important not to give out a password. Also describe why longer, more complicated passwords are important.
15 How Networks Are Structured Client/Server networkNodes and servers share data rolesNodes are called clientsServers are used to control accessDatabase softwareAccess to data controlled by serverServer is the most important computer
16 How Networks Are Structured Peer to peer networks (P2PN)All nodes are equalNodes access resources on other nodesEach node controls its own resourcesMost modern OS allow P2PNTeaching tipDiscuss how users managing their own security settings can be bad.
17 Network Topologies Topology Logical layout of wires and equipment Choice affectsNetwork performanceNetwork sizeNetwork collision detectionTeaching tipDiscuss how your network topology handles collisions. If your students are technical, contrast this with an inferior topology.
18 Network Topologies Bus topology Also called linear bus One wire connects all nodesTerminator ends the wiresAdvantagesEasy to setupSmall amount of wireDisadvantagesSlowEasy to crashTeaching tipPages 352 and 353 have diagrams of each network topology
19 Network Topologies Star topology All nodes connect to a hub Advantages Packets sent to hubHub sends packet to destinationAdvantagesEasy to setupOne cable can not crash networkDisadvantagesOne hub crashing downs entire networkUses lots of cableMost common topology
21 Network Topologies Ring topology Nodes connected in a circle Tokens used to transmit dataNodes must wait for token to sendAdvantagesTime to send data is knownNo data collisionsDisadvantagesSlowLots of cable
22 Network Topologies Mesh topology All computers connected together Internet is a mesh networkAdvantageData will always be deliveredDisadvantagesLots of cableHard to setup
24 Wire Based Media Twisted-pair cabling Most common LAN cable Called Cat5 or 100BaseTFour pairs of copper cable twistedMay be shielded from interferenceSpeeds range from 1 Mbps to 1,000 MbpsInsider informationInterference is usually electrical. Magnets, solar flares or electronic devices generate interference.
25 Wire Based Media Coaxial cable Similar to cable TV wire One wire runs through cableShielded from interferenceSpeeds up to 10 MbpsNearly obsolete
26 Wire Based Media Fiber-optic cable Data is transmitted with light pulsesGlass strand instead of cableImmune to interferenceVery secureHard to work withSpeeds up to 100 GbpsTeaching tipRemind students that bps is bits per second. Gbps then is billion bits per second.
27 Wireless Media Data transmitted through the air LANs use radio waves WANs use microwave signalsEasy to setupDifficult to secureTeaching tipNow is the time to briefly discuss standards. A full discussion of is covered in the next section.
28 Network Hardware Network interface cards Network adapter Connects node to the mediaInsider InformationThe Xerox Corporation controls the assignment of Ethernet addresses to NIC manufacturers.
29 Network Hardware Hubs Center of a star network All nodes receive transmitted packetsSlow and insecure
30 Network Hardware Switches Replacement for hubs Fast and secure Insider informationTwisted pair networks cannot achieve higher than 10 Mbps using a hub. Switches are necessary to achieve 100 Mbps or higher.
31 Network HardwareBridgeConnects two or more LANs together
32 Network Hardware Router Connects two or more LANs together Connect internal networks to the InternetNeed configured before installationDiscussion pointAsk who in the class has high speed Internet. Then determine if anyone is sharing this to the rest of the house or dorm. If they are, see if they can describe the setup. Most likely, the sharing is done with a router.
33 Network Hardware Gateway Connects two dissimilar networks Connects coax to twisted pair
34 Network Cabling Cabling specifications Bandwidth measures cable speed Typically measured in MbpsMaximum cable lengthConnector describes the type of plug
35 Network Cabling Ethernet Very popular cabling technology 10 Base T, 10Base2, 10Base5Maximum bandwidth 10 MbpsMaximum distances100 to 500 meters
36 Network Cabling Fast Ethernet Newer version of Ethernet Bandwidth is 100 MbpsUses Cat5 or greater cableSometimes called 100Base TRequires a switchTeaching tipPoint out that the speed of the cable is the number before the word Base.
37 Network Cabling Gigabit Ethernet High bandwidth version of Ethernet 1 to 10 GbpsCat 5 or fiber optic cableVideo applications
38 Network Protocols Language of the network Rules of communication Error resolutionDefines collision and collision recoverySize of packetNaming rules for computers
39 Network Protocols TCP/IP Transmission Control Protocol/Internet ProtocolMost popular protocolRequired for Internet accessTeaching tipHave students determine IP addresses for the computer. On 2000/XP enter ipconfig /all. Windows 98 and back enter winipcfg.