2 Content The Need for a Computer Network LANs and WANs Peer-to-PeerServer-ClientConnecting to a computer Networknetwork interface card (NIC)Connecting Device … switch, hub, routerNetwork cables … coaxial cable, UTP, optical fibreWireless networkNetwork Topology … bus, star, ringNetwork Operating System (NOS)
3 Common Services in a network File ServerPrint ServerApplication Server……
4 What is a computer network A computer network is a systemof interconnected computersthat can exchange information andshare resourcesresourcesfiles / data / information / documentsoftwareHardware (device : harddisk drive, floppy disk drive, CD-ROM drive, printer, scanner)
5 Uses of network governmental departments corporation / business sector educational institutionsprivate apartmentshomehotelentertainment
6 Standalone computer Powerful, valuable tools for individual use But during …. File transferby file copying, then give the disk to the otherAdv :Allow us to socialize with a friend while we exchange and merge datalow cost, more secure, low technique requiredDisadv :far too slowinefficient to meet the the need and expectation todaydepends on distances we want the data to travel
7 When networked values increase greatly Adv : Disadv : Reduce the need of paper communicationincrease efficiencynearly all type of data can be available simultaneously to every userDisadv :Less securemuch more technique required
8 The Need for a Computer Network AdvantageCommunicationResources SharingCentralized Data ManagementSoftware SharingBackupCentralized Administration
9 Communication by using email winpopup (for Win 98) messaging file transfer
10 Resources sharing share peripheral device share internet connection printerscannerCD-ROM, other storage devicesHarddisk spaceshare internet connectionshare CPU, RAM etc...
11 Centralized Data Management users can work separately in different placebut sharing the same database fileno need to update PC by PC
12 Software sharingsome software has standalone version and also network versionusing network versionlower the purchase costminimize the installation procedureminimize problem caused by configuration changes
13 Backup network backup more secure more easy minimize down time lower the cost for the backup storageroom securityequipment requirement etc...
15 Networking Classification By geographical limit / sizeLANs / WANsBy computer relationshipserver-client / peer-to-peerBy wiring layout / methodtopology (bus / star / ring / mesh)