1. Chapter 21 Topologies Chapter 2

2. 2 Chapter Objectives Explain the different topologies Explain the structure of various topologies Compare different topologies

3. Chapter 23 Recall LAN types are Ethernet, Token Ring, Token bus and Fiber Distributed Data Interface (FDDI). OSI layers are Physical, Data Link, Network, Transport, Session, Presentation and Application layer The factors of network selection criteria are Performance, Reliability and Security Standards organization is unit which develops, maintains, improves, amends and revises standards

4. Chapter 24 Introducing Topologies Topology refers to physical or logical arrangement of network Physical topologies are  Single Node  Bus  Star  Ring  Mesh  Tree  Hybrid

5. Chapter 25 Single Node Topology - I Single device, at times device called dumb terminal is connected to the server Devices operates on files from server and returns them back after completing task

6. Chapter 26 Single Node Topology - II Advantages:  Easy to install, configure and manage  Least expensive  Single cable is required Disadvantages:  Network consists of single device  Dumb terminal is dependent on server

7. Chapter 27 Bus topology - I All devices are connected to a common cable called trunk Maximum segment length of cable is 200 m Maximum of 30 devices per segment

8. Chapter 28 Bus topology - II Server is at one end and devices are at different positions 50 ohm terminator is used Devices are not responsible for data transmission Number of collisions are more Daisy chain method can be used to add more devices

9. Chapter 29 Bus topology - III Advantages:  Installation of devices is easy  Requires less cable compared to star topology  Less expensive and works better for smaller networks Disadvantages:  If backbone breaks, entire network gets down  Difficult to isolate problems  Limited number of devices

10. Chapter 210 Star Topology - I Each device is connected to a central device called hub through cable Data passes through hub before reaching destination

11. Chapter 211 Star Topology - II Advantages:  Easy to install, configure, manage and expand  Centralized management  Addition or removal of device does not affect the whole network Disadvantages:  Requires more cable  Failure of hub affects entire network  More Expensive

12. Chapter 212 Case Study 1 Hyderabad branch of the MoneyMaker bank has built an insurance department in such a way that each device is connected to one another. This department consists of seven agents. It is required that agents should handle only their specific clients since the information is confidential. But in the existing topology the data is not secured. So, Smith, the network administrator, wants to switch over to other topology.

13. Chapter 213 Problem Design a new type of network for this department.

14. Chapter 214 Suggested Solution The current topology implemented by the bank is mesh in which information is shared between different devices. To obtain security of data star network seems to be the best choice. It also provides ease of troubleshooting, centralized management and ease of reconfiguration.

15. Chapter 215 Ring Topology - I Devices are connected in a closed loop All devices have equal access to media Device waits for its turn to transmit Most common type is Token Ring

16. Chapter 216 Ring Topology - II Advantages:  Data travels at greater speed  No collisions  Handles large volume of traffic Disadvantages:  More cabling is required compared to bus  One faulty device affects the entire network  Addition of devices affect network

17. Chapter 217 Dual Ring Topology Consists of two independent primary and secondary rings Secondary ring is redundant, used only when primary stops functioning

18. Chapter 218 Mesh Topology - I Used in WANs to interconnect LANs Every device is connected to every other device Use routers to determine the best path of communication

19. Chapter 219 Mesh Topology - II Types Full mesh Partial mesh Full mesh topology – All devices are connected to each other Partial mesh topology - Some devices are connected to only those with whom they exchange most of the data

20. Chapter 220 Mesh Topology - III Advantages:  Improves fault tolerance  Failure of one link does not affect entire network  Centralized management is not required Disadvantages:  Difficult to install and manage  Each link from one device to other requires individual NIC  Very much expensive

21. Chapter 221 Tree Topology - I Connects groups of star networks Devices are wired to root hub Root hub is connected to second level devices Lowest level devices are smaller computers

22. Chapter 222 Tree Topology - II Advantages:  Easy to add new devices  Point-to-point wiring for each device  Fault detection is easy Disadvantages:  Difficult to configure  If backbone breaks, entire network goes down  More expensive

23. Chapter 223 Hybrid Topology - I Combines two or more different physical topologies Commonly Star-Bus or Star-Ring Star-Ring uses Multistation Access Unit (MAU)

24. Chapter 224 Hybrid Topology - II Advantages:  Used for creating larger networks  Handles large volume of traffic  Fault detection is easy Disadvantages:  Installation and configuration is difficult  More expensive than other topologies  More cabling is required

25. Chapter 225 Case Study 2 MoneyMaker Bank at Mumbai has implemented a star topology in their IT department. All computers are connected to the central switch. In the Loan department, all computers are connected in closed loop format. Network administrator, John wants to connect these two networks so that data can be shared among different departments.

26. Chapter 226 Problem Connect two different departments

27. Chapter 227 Suggested Solution The administrator can join these two star and ring networks to form a hybrid network with the help of Multistation Access Unit (MAU). It is a centralized hub. Ensure that there is no break in the link between two computers in a ring network and switch in star network is working properly.

28. Chapter 228 Summary - I Network is an interconnection of many communicating entities that are connected for the purpose of data communication Topology describes the way in which networking devices are connected to each other Physical topologies are how the wires are interconnected, while logical topology is how the network behaves and interoperates Different types of topologies are Single Node, Star, Bus, Ring, Mesh, Tree and Hybrid

29. Chapter 229 Summary - II In a single node topology, just a single device called dumb terminal is connected to the server Bus topology connects each device to a single cable and at either end of the cable terminator is used to remove unsent data from the cable In star topology, multiple devices are connected to a central connection point known as hub or switch In a ring topology, data travels around the loop in one direction and passes through each device

30. Chapter 230 Summary - III In a mesh topology, every device is connected to each and every node in the network with many redundant interconnections at least two paths to and from every node Tree topology connects multiple star networks to other star networks using bus topology Hybrid topology is a combination of different topologies such as Star-Bus or Star-Ring