This document discusses different network topologies. It defines topology as the arrangement of links, nodes, and other elements in a computer network. There are two main categories: physical and logical topologies. For physical topologies, it describes linear bus, star, tree, ring, and mesh configurations. Each has advantages, like easy installation for stars, and disadvantages, such as a single point of failure for the central hub. Logical topology refers to how information passes between nodes. The document examines characteristics of each physical topology type in detail.

1. “Network Topologies”
By Pavan Kumar B N

2. What is Topology?
 Network topology is the arrangement of the various elements
(links, nodes, etc.) of a computer.
 There are two basic categories of network topologies.
1 Physical topologies-The physical topology of a network refers
to the configuration of cables, computers, and other peripherals.
2 Logical topologies- Is the method used to pass information
between workstations.

3. Main Types of Physical Topologies
 Linear Bus.
 Star.
 Tree (Expanded Star).
 Ring.
 Mesh.

4. Linear Bus Topology..
 A linear bus topology consists of a main run of cable with a terminator at each end .
 All nodes (file server, workstations, and peripherals) are connected to the linear
cable.
Disadvantages
Entire network shuts down if there is a break in the main
cable.
Terminators are required at both ends of the backbone
cable.
Difficult to identify the problem if the entire network shuts
down.
Advantages
Easy to connect a computer or peripheral to a linear
bus.
Requires less cable length than a star topology.
Works well for smaller networks.

5. Star Topology
 A star topology is designed with each node (file server, workstations, and
peripherals) connected directly to a central network hub, switch, or
concentrator.
 Data on a star network passes through the hub, switch, or concentrator
before continuing to its destination.
 The hub, switch, or concentrator manages and controls all functions of the
network.

6. Contd..
Advantages of a Star Topology
 Easy to install and wire.
 No disruptions to the network when connecting or removing devices.
 Easy to detect faults and to remove parts
Disadvantages of a Star Topology
 Requires more cable length than a linear bus topology.
 If the hub, switch, or concentrator fails, nodes attached are disabled.
 More expensive than linear bus topologies because of the cost of the hubs,
etc.

7. Tree or Expanded Star
 A tree topology combines characteristics of linear bus and star topologies.
 It consists of groups of star-configured workstations connected to a linear
bus backbone cable.
 Tree topologies allow for the expansion of an existing network.

8. Contd..
Advantages of a Tree Topology
 Point-to-point wiring for individual segments.
 Supported by several hardware and software venders.
Disadvantages of a Tree Topology
 Overall length of each segment is limited by the type of cabling used.
 If the backbone line breaks, the entire segment goes down.
 More difficult to configure and wire than other topologies.

9. Ring Topology
 A network topology that is set up in a circular fashion in which data travels
around the ring in one direction and each device on the right acts as a
repeater to keep the signal strong as it travels.
 Each device incorporates a receiver for the incoming signal and a
transmitter to send the data on to the next device in the ring.

10. Contd..
Advantages:
 Data packets travel at great speed
 No collisions.
 Easier to fault find.
Disadvantages:
 Requires more cable than bus.
 A break in the ring will bring it down

11. Mesh Topology
 some or all of the devices are connected to more than one other device.
A fully connected mesh topology is one in which every device is
connected to every other device. This makes it possible for one device to
send data to all other devices simultaneously. This is usually considered too
complex and costly for large networks.

12. Contd..
Advantages
 Improve fault tolerance.
 Can carry more data.
Disadvantages
 Expensive
 Difficult to manage.
 Difficult to trouble shoot

13. Why multiple topologies?
Each has advantages and disadvantages
 Ring ease synchronization; may be disabled if any cable is cut.
 Star easier to manage and more robust;
requires more cables.
 Bus requires fewer cables; may be disabled if cable is cut.
 Industry setting on start topology as most widely used.

14. Factors on deciding topology
 Cost
 Scalability
 Bandwidth capacity
 Ease of installation
 Ease of fault finding and maintenance.

15. Thank You