Chapter 2 1

Topologies

Chapter 2

Chapter 2 2

Connectivity

Communication is a transfer information from one place to another place. There are two type of signal: Base band : Single time single data. Broadband : Single time multi data

Chapter 2 3

Introducing Topologies Topology Provide the different configuration that are

use to create a network. Network is a collection of computer connected with each other.

Physical topologies are Single Node Bus Star Ring Mesh Tree Hybrid

Chapter 2 4

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

Chapter 2 5

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

Chapter 2 6

Bus topology - I All devices are connected to a common cable called

trunk or back bone cable Maximum segment length of cable is 200 m Maximum of 30 devices per segment

Chapter 2 7

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

Chapter 2 8

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

Chapter 2 9

Star Topology - I Each device is connected to a central device called

hub or switch through cable Data passes through hub before reaching

destination

Chapter 2 10

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

Chapter 2 11

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

Chapter 2 12

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

Chapter 2 13

Dual Ring Topology

Consists of two independent primary and secondary rings

Secondary ring is redundant, used only when primary stops functioning

Chapter 2 14

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

Chapter 2 15

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

Chapter 2 16

Tree Topology - I

Connects groups of star networks

Devices are wired to root hub

Root hub is connected to second level devices

Chapter 2 17

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

Chapter 2 18

Hybrid Topology - I

Combines two or more different physical topologies Commonly Star-Bus or Star-Ring Star-Ring uses Multistation Access Unit (MAU)

Chapter 2 19

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