Networking basics
- 1. NetworkingBasics Presented By: Sahil Showkat E-mail: sahil@pearlx.in Website: www.pearlx.in
- 2. Network Group of two or more computers interconnected to share resources, exchange data or allow electronic communication is called as a network. The communication between two or more interconnected devices is called networking. An internetwork is a connection of two or more networks. Internetworking means communication between different networks.
- 3. The Uses of a Network Simultaneous access to data Data files are shared Access can be limited Shared files stored on a server Software can be shared
- 4. Sharing Data File server contains documents used by other computers.
- 5. The Uses of a Network Personal communication Email Instantaneous communication Conferencing Tele conferencing Videoconferencing Audio-conferencing Data-conferencing Voice over IP Phone communication over network wires
- 7. The Uses of a Network Easier data backup Backup copies data to removable media Server data backed up in one step
- 8. The Uses of a Network Hardware Sharing Printers, scanners and devices can be shared.
- 9. Types of Networks LAN Local Area Networks are used to connect networking devices that are in a very close geographic area such as a floor of a building, a building itself or within a campus. MAN Metropolitan Area Network are used to connect networking devices that may span around the entire city. WAN Wide Area Networks which connects two or more LANs present at different geographical locations.
- 13. Network Operating System A network operating system is a software application that provides a platform for both the functionality of an individual computer and for multiple computers within an interconnected network. A Network Operating System (NOS) is a software program that controls other software and hardware running on a network. It also allows multiple computers, known as network computers, to communicate with one central hub and each other to share resources, run applications, and send messages.
- 14. Types of NOS’s There are two major types of network operating systems: Peer-to-Peer Client/Server
- 15. Peer-to-Peer In Peer-to-Peer NOS, all computers share equivalent responsibility for processing data. They have same abilities to use the resources available on the network. They don’t have a centralized management source.
- 16. Advantages It is easy to install and so is the configuration of computers on this network. All the resources and contents are shared by all the peers, unlike server-client architecture where Server shares all the contents and resources. P2P is more reliable as central dependency is eliminated. Failure of one peer doesn’t affect the functioning of other peers. There is no need for full-time System Administrator. Every user is the administrator of his machine. User can control their shared resources. The over-all cost of building and maintaining this type of network is comparatively very less.
- 17. Disadvantages In this network, the whole system is decentralized thus it is difficult to administer. Security in this system is very less. Viruses, spywares, trojans, etc malwares can easily transmitted over this P-2-P architecture. Data recovery or backup is very difficult. Each computer should have its own back-up system
- 18. Client/Server In Client Server NOS there is one powerful computer (known as server) which acts as a provider of information to other sub-ordinate workstations (called client). Server becomes the heart of the system, providing access to resources and providing security.
- 19. Advantages There is a centralized control. Servers help in administering the whole set-up. Access rights and resource allocation is done by Servers. All the files are stored at the same place. In this way, management of files becomes easy. Also it becomes easier to find files. As all the data is stored on server its easy to make a back-up of it. Also, in case of some break-down if data is lost, it can be recovered easily and efficiently. Rules defining security and access rights can be defined at the time of set-up of server.
- 20. Disadvanatges Too many requests from the clients may lead to congestion, which rarely takes place in P2P network. Overload can lead to breaking-down of servers. If the server fails, the whole network goes down. It is very expensive to install and manage this type of computing.
- 21. Topology Topology is a physical layout of the systems connected in a network. Different types of topology are: Bus Star Tree Choice affects Network performance Network size Network collision detection
- 22. Linear Bus Topology In bus topology all devices are connected to a single cable or backbone. It supports half duplex communication.
- 23. Advantages Easy to setup. Requires less cable length. Disadvantages A break at any point along the backbone will result in total network failure.
- 24. Star Topology The most commonly used topology It consist of one centralized device which can be either a switch or a hub. The devices connect to the various ports on the centralized devices. HUB/Switch
- 25. Advantages Easy to setup. Easy to add/remove parts Disadvantages One hub crashing downs entire network. Uses lots of cable
- 26. Tree Topology A tree topology combines the characteristics of linear bus and star topology. It consist of groups of star configured workstations connected to a linear bus backbone cable.
- 27. Advantages Expansion of Network is possible and easy. We divide the whole network into segments (star networks), which can be easily managed and maintained. Each segment is provided with dedicated point-to-point wiring to the central hub. If one segment is damaged, other segments are not affected. Disadvantages Because of its basic structure, tree topology, relies heavily on the main bus cable, if it breaks whole network is crippled. More difficult to configure.
- 28. Ring Topology In ring topology each computer or device is connected to its neighbor forming a loop.
- 29. Advantages Each computer has equal access to resources. There is no need for network server to control the connectivity between workstations. Disadvantages Failure of a single device or a break anywhere in the cable causes the full network to stop communicating. Each packet of data must pass through all the computers between source and destination. This makes it slower than Star topology. If one workstation or port goes down, the entire network gets affected.
- 30. Mesh Topology In mesh topology each device is directly connected to all other devices. In fact a true mesh topology is the one where every node is connected to every other node in the network. This type of topology is very expensive as there are many redundant connections
- 31. Advantages Data can be transmitted from different devices simultaneously. This topology can withstand high traffic. Even if one of the components fails there is always an alternative present. So data transfer doesn’t get affected. Expansion and modification in topology can be done without disrupting other nodes. Disadvantages There are high chances of redundancy in many of the network connections. Overall cost of this network is way too high as compared to other network topologies. Set-up and maintenance of this topology is very difficult. Even administration of the network is tough.
- 32. Network Media Links that connect nodes. Communication channel through which data travels on a network. Choice impacts Speed Security Size
- 33. Wire Based Media (guided) Twisted-pair cable Most common LAN cable Four pairs of copper cable twisted May be shielded from interference Speeds range from 1 Mbps to 1,000 Mbps
- 34. Wire Based Media (guided) Coaxial cable Similar to cable TV wire One wire runs through cable Shielded from interference Speeds up to 10 Mbps
- 35. Wire Based Media (guided) Fiber-optic cable Data is transmitted with light pulses Glass strand instead of cable Immune to interference Very secure Hard to work with Speeds up to 100 Gbps
- 36. Wireless Media (unguided) Data transmitted through the air LANs use radio waves WANs use microwave signals Easy to setup Difficult to secure
- 37. Networking Devices Networking devices include all the equipment needed to perform data-processing and communications within the network. Network Interface Card Repeaters Concentrator/Hubs Bridges Switches Routers
- 38. Network Interface Card A NIC, typically an expansion card in a computer, is used to connect a system to physical network media. Nowadays, computers are equipped with a built-in NIC. NICs are available for different types of network media, the most common today being Ethernet NICs with a RJ-45 Socket for twisted pair cabling and wireless network adapters with antenna.
- 39. Ethernet Card
- 41. Token Ring Card
- 42. Repeater Repeaters clean, amplify, and resend signals that are weakened by long cable length. Can be separate or built-in to hubs or switches Most economic way of expanding a network. The number of repeaters must be limited. Repeaters cannot connect different network architecture. Repeater do not reduce network traffic. Half –Duplex Communication.
- 43. Hub/Concentrators Hubs regenerate and retime network signals. They are really multi-port repeaters. Hubs propagate signals through the network They cannot filter network traffic They cannot determine best path Uplink port – crossover mode or straight through mode
- 46. Bridges Bridges are more intelligent than hubs. They increase network performance by segmenting networks in separate collision domains. They maintains a table with MAC Addresses of all attached nodes and on which segment they are located. Filter traffic by looking at the MAC address. Used for connecting two different topology (Segment). If the frame is addressed to a MAC address on the local side of the bridge, it is not forwarded to the other segment Bridges maintain a MAC address table for both segments they are connected to
- 47. Switches It is an Intelligent device. It maintains MAC address table (hardware address). Switches resemble bridges and can be considered as multiport bridges. Each port of the switch has fixed bandwidth. Supports full duplex communication.
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- 49. Functions of Switch MAC ADDRESS TABLE PORT MAC- ADDRESS 1 2 3 4 5 6 7 8 001C-C01A-0002 001C-C01A-0004 001C-C01A-0002 1 2 3 4 5 6 7 8 S D DataDataDataDataDataData Data Source MAC 001C.C01A.0002 Destination MAC 001C.C01A.0004 DATA Source MAC 001C.C01A.0002 Destination MAC 001C.C01A.0004 DATA
- 50. MAC ADDRESS TABLE PORT MAC- ADDRESS Fa0/1 Fa0/2 001C-C01A- 0002 Fa0/3 Fa0/4 Fa0/5 Fa0/6 Fa0/7 Fa0/8 001C-C01A-0004 001C-C01A-0002 001C-C01A-0004 1 2 3 4 5 6 7 8 D S Data
- 51. Types of Switches Unmanaged Switch Managed Switch Smart Switch Enterprise managed Switch
- 52. Router These are physical devices that join multiple wired and wireless networks together. Routers select the best path to route a message, based on destination address and origin. The router can direct traffic to prevent head-on collisions. Routers know the addresses of computers, bridges and other routers on the network. Routers usually uses the IP Addresses