1

Submitted To: Prof. Imran

Rafique Submitted

By: Aqsa

Ashraf Roll No:

0031-BH-2018. Section:

G-1 Course code:

CA-1201 Topic:

“Different network Topologies”

Contents

What is topology?....................................... Types of network topology…………...…... Bus topology……………………………….

i. Features

2

ii. Advantagesiii. Disadvantages

Ring topology …………………….................i. Features

ii. Advantages iii. Disadvantages

Star topology……………………………….i. Features

ii. Advantagesiii. Disadvantages

Mesh topology………………………………

Types…………

Flooding routing

i. Features ii. Advantagesiii. disadvantages

Tree topology ………………………………i. Features

ii. Advantagesiii. Disadvantages

Hybrid topology………………………….iv. Featuresv. Advantages

vi. disadvantages

What is topology?

Network topology is the arrangement of the elements of a communication network. It can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial field busses, and computer networks. It is the topological structure of a network and may be depicted physically or logically. Physical

3

topology is the placement of various components of a network, while logical topology illustrates how data flows within a network. A network’s physical topology is a particular concern of the physical layer of OSI model. Examples of network topologies are found in local area network.

Types of network topology

It is the schematic description of network arrangement, connecting various nodes through lines of connection.

Bus topology

It is a network type in which every computer and network device is connected to a single cable. When it has exactly two endpoints, then it is called linear bus topology.

Features of bus topology

It transmits data only in one direction. Every device is connected to a single cable.

Advantages

It is cost effective. =Cable required is least compared to other network topology. Used in small networks. Easy to understand. Easy to expand joining two cables together.

Disadvantages

Cables fail, then whole network fail. If network traffic is heavy, then performance decreases. Cable has a limited length.

4

It is slower than a ring topology.

Ring topology

It is called ring because it forms ring as each computer is connected to another computer with the last one connected to the first. Exactly two neighbours for each device.

Features of ring topology

A number of repeaters are used for ring topology with large number of nodes, because if someone wants to send some data to the last node in the ring topology with 100 nodes, then the data will have to pass through 99 nodes to reach 100th node.

The transmission is uni-directional but it is made bidirectional by having 2 connections between each network node, called dual ring topology.

In dual ring topology, two ring networks ae formed and data flow in opposite direction in them.

Data is transferred in a sequential manner that is bit by bit. Data transmitted has to pass through each node of the network, till the destination node.

Advantages

Transmitting network is not affected by high traffic or by adding more nodes, as only the nodes having tokens can transmit data.

Cheap to install and expand.

Disadvantages

troubleshooting is difficult in ring topology.

5

Adding or deleting the computer disturbs the network activity. Failure of one computer disturbs the whole network.

Star topology

In this type of topology, all the networks are connected to a single hub through a cable. This hub is a central node and all other nodes are connected to the central node.

Features of star topology

Every mode has its own dedicated connection to hub. Hub acts as repeater for data flow. Can be used with twisted pair, optical fiber or coaxial cable.

Advantage

Fast performance with few nodes and low network traffic. Hub can be upgraded easily. Easy to troubleshoot. Easy to setup and modify. Only that node is affected which failed, rest of the nodes can work smoothly.

Disadvantages

Cost of installation is high. Expensive to use. If the hub fails, the whole network is stopped. Performance is based on the hub that is; it

depends on its capacity.

Mesh topology

6

It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. There are two techniques to transmit data over the mesh topology. These are:

Routing

Flooding

Mesh topology: Routing

The node has a routing logic as per the network requirements. Routing logic to direct the data to reach the destination using the shortest distance. We can even have the routing logic to re-configure the failed nodes.

Mesh topology: flooding

The same data is transmitted to all the network nodes, hence no routing logic is required. It leads to unwanted load over the network.

7

Types of mesh topology

1. Partial mesh topology: some of the systems are connected in the same fashion as mesh topology but some devices are only connected to two or three devices.

2. Full mesh topology: each and every nodes are connected to each other.

Features

1. Robust2. Connected3. Not flexible

Advantages

It is robust Fault can be diagnosed very easily Provides privacy and security

Disadvantages

More cabling cost Bulk wiring required Difficult to install

Tree topology

It has a root node and all the other nodes are connected to it and form a hierarchy. It is also called a hierarchical topology.

8

Features

Ideal for group workstations Used in wide area network

Advantages

Extension of bus and star topologies Expansion of node is easy Can be easily managed Error detection is easy

Disadvantages

Expensive Heavily cabled Network fails when central hub fails

Hybrid topology

It is a mixture of two or more topologies. For example if ring topology and star topology are combined, hybrid topology results.

9

Features

Combination of two or more topologies Inherits the advantages and disadvantages of the included topologies

Advantages

Reliable Troubleshooting is easy Flexible Effective

Disadvantages

Expensive Have complex design

References

www.studytonight.com fossbytes.com/what-is-network-topology www.lifewire.com techspirited.com www.wedopedia.com

10