Network Topology used in computer network.pptx

Networktopology

1. Topic – Network Topology Anurag Chachan 15IT002

2. Network Topology A network topology is the  arrangement of a network (i.e. geometry), including its nodes and connecting lines.   There are 2 ways of defining Network Geometry i.e. Physical Topology . Logical Topology. 2

3. Network Topology ( cont …) Physical Topology Refers to Actual Geometric Layout of the network. Decides Structure of a network i.e. which wire will connect to which node? Logical Topology Refers to How Data Moves Through the network Decides How Communication is done? 3

4. Physical Topology 4 Geometric Representation of the relationship of all links connecting the devices or nodes. Two Relationship are possible. 1. Peer to Peer :- device shares link equally. Example – Ring & Mesh Topology 2. Primary – Secondary :- One device controls and other device have to transmit through it. Example – Star & Tree Topology

5. Physical Topologies Bus Ring Star Mesh Tree Hybrid 5

6. Bus Topology All networked nodes (Network Device, Computer) are interconnected, using a single cable . Only one device transmits at a time. Passive topology i.e. cable will only receive signal & broadcast it without any modification. 6

7. Advantages of Bus topology Easy to implement & understand . Well suited for small networks . Cheapest topology. Failure of one station does not affect others. Easy to expand by joining two cables with BNC barrel connector . 7

8. Disadvantages of Bus topology Difficult to administer/troubleshoot . Limited cable length and number of stations. A cable break can disable the entire network . Maintenance costs may be higher in the long run . Performance degrades on adding more nodes/computers. 8

9. Ring Topology Started out as a simple peer-to-peer LAN topology Each networked workstation had two connections i.e. one to each of its nearest neighbours . Data is transmitted unidirectionaly. Concept of Token Passing was introduced later on as to avoid transmission by one node only. 9

10. Token Passing Token contains a piece of information which along with data is sent by the source node. This token then passes to next node , which checks if the signal is intended to it If yes , it receives it and passes empty token to next node. otherwise passes token along with the data to next node 10

11. Advantages of Ring topology No monopoly of a node because each node is given equal access to token. Performance is better than that of Bus topology No need for network server to control the connectivity between nodes. Additional components do not affect the performance of network like Repeaters. 11

12. Disadvantages of Ring topology Each packet of data must pass through all the nodes between source and destination. If one node goes down, the entire network gets affected. Network is highly dependent on the wire which connects different components. Adding/Deleting the nodes disturbs network. 12

13. Star Topology All the nodes are connected to a single hub (central node) through cable. Each networked device have to communicate to other via hub only. Hub broadcasts signal to all the computer on network & intended node receives it. Switch as central node makes communication dedicated i.e. signal sent to only intended recipient. 13

14. Advantages of Star Topology Compared to Bus topology it gives far much better performance. Easy to expand. Easy to monitor and troubleshoot. Failure of one node doesn’t affect the rest of network. Hub/Switch can be upgraded easily. 14

15. Disadvantages of Star T opology If central device fails whole network goes down The use of hub, a router or a switch as central device increases the overall cost of the network High cabling cost. Performance depends on capacity of hub/switch. 15

16. Mesh Topology All the nodes have dedicated point to point link to every other node. Techniques to transmit data Routing:- Nodes have a routing logic . Like to direct data to destination. Flooding:- No routing logic , data is flooded i.e. sent to each node. 16

17. Advantages of Mesh Topology Each connection can carry its own data load (dedicated link). It is robust- Failure of single node doesn’t bring down the entire network. Fault is diagnosed easily. Provides security and privacy as data travels over dedicated line. 17

18. Disadvantages of Mesh Topology Installation and Reconfiguration is difficult. Cabling cost is more. Bulk wiring is required. Hardware required to connect each link and cable is expensive. 18

19. Tree Topology It has a root node ( Central Hub ) , nodes are connected to central hub that controls the traffic. Not every node is connected to central hub, most of them are connected to secondary hub which in turn is connected to central hub. Central Hub is an active hub which contains repeater. Other hubs are secondary hubs (active or passive). 19

20. Advantages of Tree Topology Extension of bus and star topologies. Expansion of nodes is possible and easy. Easily managed and maintained. Error detection is easily done. Allows the devices to attach to single hub & therefore, increases the distance of a signal can travel between devices. 20

21. Disadvantages of Tree Topology Heavily cabled. Costly. If more nodes are added maintenance is difficult. Central hub fails, network fails. 21

22. Hybrid Topology It is a mixture of two or more topologies. For example:- In an office in one department ring topology is used and in another star topology is used & in another bus topology is used, connecting these topologies will result in Hybrid Topology i.e. ( Ring T opology , S tar T opology, Bus Topology ). 22

23. Advantages of Hybrid Topology Reliable :- Error detecting and trouble shooting is easy . Effective :- Mixture of 2 topologies therefore we can design in such a way that strength or topologies are maximised and weakness minimised. Scalable :- size can be increased easily without disturbing network. Flexible :- can be designed according to requirements and resource available. 23

24. Disadvantages of Hybrid Topology Complex in design:- Not easy to design such an architecture. Costly infrastructure:- as it requires a lot of cables, cooling system, network devices like hub. 24

25. Logical Topology The way nodes are logically connected to each for the purpose of exchange of data. For example:- for a bus topology , the bus/cable acts as central controller. It receives the data and forward it to various nodes. Therefore, it is logically start topology but bus topology by physically. 25

26. 26 Thank You