1. Prepared by Abegail T. SoasJanuary 2012

2. I. Introduction II. Network Hardwarea. (By service) Two Main Typesb. (By scope/scale) Area Network III. Types c. (By physical communication scheme) Network Topologies IV. OSI Modela. Network BandwidthV. Network Performanceb. Network Throughputc. Network LatencyReferences & Video Link 3. HistoryDefinitionApplications 4. INTRODUCTION Networking began its infancy in the mid - 1960s by the US Department of Defense (DoD). The original intention of networking was being developed to withstand a nuclear war. 5. INTRODUCTION Networks are collections of computers, software, and hardware that are all connected to help their users work together. 6. INTRODUCTIONAnetwork connects computers by means of cabling systems, specialized software, and devices that manage data traffic. 7. ResourceSharing Hardware (computing resources, disks, printers) Software (application software) InformationSharing Easy accessibility from anywhere (files, databases) Search Capability (WWW) Communication Email Message broadcast Remotecomputing Distributed processing 8. The distribution of applications and business logic acrossmultiple processing platforms. Distributed processing implies that processing will occur on more thanone processor in order for a transaction to be completed. In other words, processing is distributed across two ormore machines and the processes are most likely notrunning at the same time, i.e. each process performs partof an application in a sequence. Often the data used in a distributed processing environment is alsodistributed across platforms. 9. Workstation Network Distribution(Network Cables | Hub | Router) 10. NETWORK HARDWARE In a network, computers and optional other devices are connected to share resources. When a computer or device A is requesting a resource from another computer or device B, the item A is referred to as a client. 11. NETWORK HARDWARE Becauseall or most items that are part of a network live in association or cooperation, almost any one of them can be referred to as a client. Basedon this, there can be different types of clients. The most regularly used of them is referred to as a workstation. 12. NETWORK HARDWAREa computer that optimizes the userinterface, relying on servers to handle themore mundane tasks associated with application and file storage, network administration, security, and other critical functions. 13. NETWORK HARDWARE is a computer on which a person performs everyday regular assignments. 14. NETWORK HARDWAREa computer that supplies data or resources to other machines on a network 15. NETWORK HARDWARE 1TB expandable storage for $400 16. NETWORK HARDWARE The server room at the new Facebook data center in Prineville,Oregon, featuring a hot aisle containment system. 17. NETWORK HARDWARE This one is shown coupled together with a second open frame rack. 18. NETWORK HARDWARE Building a network consists partly of connecting the computers One way to do this is to use cables. 19. NETWORK HARDWARE NETWORK CABLES Cable is used to connect computers. In our network, we will use Category 5 cable RJ- 45. The ends of the cable appear as follows: 20. NETWORK HARDWARE NETWORKCABLES Category 5 cable RJ-45 Registered jack 45 standard type of connector for network cables such as those used in Ethernet networks standard connector utilized on 4-pair (8-wire) UTP (Unshielded Twisted Pair) cable 21. NETWORK HARDWARE HUB A hub is rectangular box that is used as thecentral object on which computers and otherdevices are connected. To make this possible, a hub is equipped withsmall holes called ports. 22. NETWORK HARDWARE HUB A hub can be equipped with 4, 5, 12, or more ports 23. NETWORK HARDWARE ROUTER: Wired or Wireless Like a hub, a router is another type of device that acts as the central point among computers and other devices that are part of a network. A router can be considered a little "intelligent" than the hub. 24. NETWORK HARDWARE ROUTER:Wired or Wireless A router can be considered a little "intelligent" than the hub.Wireless Wired 25. NETWORK HARDWARE NETWORK CARD: Wired or Wireless In order to connect to a network, a computer must be equipped with a device called a network card. A network card or a network adapter, also called a network interfacecard, or NIC allows a computer to connect to the exterior. 26. NETWORK HARDWARE NETWORK CARD: Wired or Wireless A wired network card looks like a printed circuit board with some objects "attached" or "glued" to it 27. NETWORK HARDWARE NETWORK CARD: Wired or Wireless A wireless NIC appears as its wired counterpart 28. BY SERVICEPeer-to-Peer(Definition | Network Setup | Benefits | Limits) Client/Server (Definition | Benefits | Limits) 29. 2 MAIN TYPESA peer-to-peer network allows any user to share files with any other userand doesnt require a central, dedicated server.A network is referred to as peer-to-peer ifmost computers are similar and runworkstation operating systems 30. 2 MAIN TYPES Ina peer-to-peer network, each computerholds its files and resources. Othercomputers can access these resourcesbut a computer that has a particular resourcemust be turned on for other computers toaccess the resource it has. For example, if a printer is connected to computer A and computer B wants to printer to that printer, computer A must be turned On. 31. 2 MAIN TYPES 32. 2 MAIN TYPES 33. 2 MAIN TYPES PhysicalConnection WiredNetworking Uses router toconnect thecomputers 34. 2 MAIN TYPES PhysicalConnection WirelessNetworking Uses router toconnect thecomputers 35. 2 MAIN TYPES BENEFITS Inexpensive to set up. It uses the built in networking capabilities ofWindows XP Professional (or Vista Business), sono special software is needed. It allows for file and printer sharing, and can be anadequate choice for a very small office. 36. 2 MAIN TYPES LIMITS Networkand data security are weak. Files are not centralized, so getting a back up ofall critical files is more difficult. 37. 2 MAIN TYPES LIMITS Ongoingtasks like anti-virus scanning andWindows updates are localized on eachmachine. Updating virus definitions and patches has to be donemanually at each machine, which is time consuming. 38. 2 MAIN TYPES usesone or more dedicated machines (theserver) to share the files, printers, andapplications 39. 2 MAIN TYPES 40. 2 MAIN TYPES 41. 2 MAIN TYPES Client/server describes the relationship between twocomputer programs in which one program, the client, makes a service request from another program, the server, which fulfills the request. In a network, the client/server model provides aconvenient way to interconnect programs that aredistributed efficiently across different locations. 42. 2 MAIN TYPES Computer transactions using theclient/server model are very common. For example, to check your bankaccount from your computer, a clientprogram in your computer forwards yourrequest to a server program at the bank. That program may in turn forward the requestto its own client program that sends a requestto a database server at another bankcomputer to retrieve your account balance. The balance is returned back to the bank dataclient, which in turn serves it back to the clientin your personal computer, which displays theinformation for you. 43. 2 MAIN TYPES BENEFITS The server stores all of the shared files for each user Files and resources are centralized runs the file backups manages user security and insures all users whoaccess the network are authorized to do so Username and password 44. 2 MAIN TYPES BENEFITS The server manages printer sharing and acts as a centralrepository for the printer drivers and settings Manages other common tasks such as internetaccess, email routing, Windows updating, andanti-virus definition management 45. 2 MAIN TYPES BENEFITS The server can also share software applications out to multiple users provide for an Intranet, an internal website whichholds shared company information such as newsannouncements, HR policies, training documents,and more 46. 2 MAIN TYPES BENEFITS In short, this network provides for easier network administration, and provides a much more robust environment in which provide secure and manageable access to company data. 47. 2 MAIN TYPES LIMITSAserver based computer network is moreexpensive to implement. Server computers are powerful machines with built-inredundancy and other hardware to provide data safety. Hence, they cost much more than a simple desktopcomputer. 48. 2 MAIN TYPES LIMITS The server network software is also much more powerful, complicated, and must be installed correctly to run all of the requiredtasks, and so the cost is higher for both the softwareand installation charges. 49. 2 MAIN TYPES LIMITS Theserver is a critical point of failure. If it goesdown, the entire network comes to a halt. This drawback can be minimized with the installationof redundant drives in the server (so that if one fails,the others will still be working), and even a second server that can take over if theprimary server fails completely. Cost then becomes the only issue. 50. BY SCOPE / SCALE LAN WAN 51. TYPES BY SCOPE / SCALE Oneway to categorize the different typesof computer network designs is by theirscope or scale. For historical reasons, the networkingindustry refers to nearly every type ofdesign as some kind of area network. 52. TYPES BY SCOPE / SCALE Standsfor Local Area Network Usually denotes a network of computerswhich are fairly close together, say in thesame building or office. 53. TYPES BY SCOPE / SCALE Standsfor Wide Area Network Usuallyconnect local area networks whichare separated by great distances 54. BY PHYSICAL COMMUNICATION SCHEMEBusStarRing 55. TYPES BY PHYSICAL COMMUNICATION SCHEME Thenetwork topology defines the way in which computers, printers, and other devices are connected.A network topology describes the layout of the wire and devices as well as the paths used by data transmissions. 56. TYPES BY PHYSICAL COMMUNICATION SCHEME physical communication scheme used by connected devices More complex networks can be built as hybrids of two or more of these basic topologies. 57. TYPES BY PHYSICAL COMMUNICATION SCHEME 58. TYPES BY PHYSICAL COMMUNICATION SCHEME Bus topology allows information to bedirected from one computer to the other.Lots of binary collision. Commonly referred to as a linear bus,all the devices are connectedby one single cable. 59. TYPES BY PHYSICAL COMMUNICATION SCHEMEStar topology is the most common type used. All computers are attached to a hub.Less collisions and most efficient. The star topology is the most commonly usedarchitecture in Ethernet LANs. When installed, the star topology resembles spokesin a bicycle wheel. 60. TYPES BY PHYSICAL COMMUNICATION SCHEMELarger networks use the extended star topology also called tree topology. When used with network devices that filter frames or packets, like bridges, switches, and routers, this topology significantly reduces the traffic on the wiresby sending packets only to the wires of thedestination host. 61. TYPES BY PHYSICAL COMMUNICATION SCHEME 62. TYPES BY PHYSICAL COMMUNICATION SCHEME A frame travels around the ring,stopping at each node. If a nodewants to transmit data, it adds the data as well as the destinationaddress to the frame.The frame then continues around the ring until it finds the destination node, whichtakes the data out of the frame.A disadvantage of a token ring is if one computer is broken or down, themessage cannot be passed to theother computers. 63. TYPES BY PHYSICAL COMMUNICATION SCHEMEThe mesh topology connects all devices (nodes) to each other forredundancy and fault tolerance.It is used in WANs to interconnectLANs and for mission critical networks like those used by banksand financial institutions. Implementing the mesh topology is expensive and difficult. 64. OSI MODEL OpenSystems Interconnection TheOSI model defines internetworking in terms of a vertical stack of seven layers. 65. OSI MODEL The OSI model was introduced in 1984. Although it was designed to be an abstractmodel, the OSI model remains a practicalframework for todays key networktechnologies like Ethernet and protocolslike IP. 66. OSI MODEL 67. OSI MODEL Modular approach to network functionality Example:ApplicationApplication-to-application channelsHost-to-host connectivityLink hardware 68. OSI MODEL Module in layered structure Set of rules governing communicationbetween network elements (applications,hosts, routers) Protocols define: Interface to higher layers (API) Interface to peer Format and order of messages Actions taken on receipt of a message 69. OSI MODEL Eachlayer relies on services from layer below and exports services to layer above Interface defines interaction Hidesimplementation - layers can change without disturbing other layers (black box) 70. OSI MODEL1) Physical: how to transmit bits2) Data link : how to transmit frames3) Network : how to route packets4) Transport : how to send packets end2end5) Session : how to tie flows together6) Presentation: byte ordering, security7) Application : everything else 71. OSI MODEL Application Presentation Session Transport Network Data Link PhysicalHost Switch Router Host 72. BandwidthThroughput Latency 73. NETWORK PERFORMANCE supporteddata rate of a network connection or interface refers to the capacity since having a higher capacity means you are able to get more data through in the same time period, the end result is that the time taken for your to view and download your content is shorter 74. NETWORK PERFORMANCE actual data rate 75. NETWORK PERFORMANCE Latencyrefers to a data packets round-trip time (RTT) i.e. the time it takes a network packet to travel from source host to its destination and back. end-to-endrate of data transmission i.e. the amount of data that actually gets transmitted from your PC, through the Internet to the web server and back in a single unit of time. This 76. NETWORK PERFORMANCE Network performance, i.e. its speed and capacity, are defined by bandwidth and latency. Bandwidth and latency are connected: bandwidth latency increases if too little bandwidth is available. In order to ensure good network performance, it is therefore important to monitor both bandwidth and latency. 77. NETWORK PERFORMANCE Ingeneral, bandwidth and throughput get a lot of attention, while latency gets little. Yet latency considerations are very important for many real-time applications such as streaming audio and video and interactive gaming. 78. http://compnetworking.about.com http://www.functionx.com/networking/ http://www.sensible-computer-help.com/computer-network.html http://www.server-racks.com/ 79. How Wifi Works - YouTube http://www.youtube.com/watch?v=t7-gIzPv9Yg&feature=related How the Internet Works - YouTube http://www.youtube.com/watch?v=Jj6EHgSsx_U&feature=related Computer Networking Tutorial 1 - YouTube http://www.youtube.com/watch?v=TVvEheZVwdg Computer Networking Tutorial - 4 - OSI Model Physical Layer http://www.youtube.com/watch?v=DqOvu-wAAM0 Bandwidth vs. Throughput - YouTube http://www.youtube.com/watch?v=VWxGtl5J7WM&feature=fvwrel