Network topology
A network can be sonfiguret or arranged in different ways. The physical layout or arrangement of connected devices in a network is called network topology. It is the shape of a network.
Types of topology.
1. Bus Topology
2. Star Topology
3. Ring Topology
4. Tree Topology
5. Mesh Topology
01. Bus Topology
Bus topology is the simplest type of network its supports a small number of computers. In bus topology all computers or network nodes are connected to a common communication medium. This medium is known as bus or backbone. The terminators are used at the end of a bus to absorb the signals and stop them to travel backwards. A collicion can occur in bus topology if to computers transmit data at the same time.
Working of Bus Network
The sending computer sends the data and destination address through the bus. The data and address move from one computer to the other in the network. Each computer checks the address. If it matches with the address of a computer, the computer keeps the data. Otherwise the data moves to the next computer.
Advantages
1. It is simple and easy to use.
2. It requires small length of cable to connect computer.
3. It is less expensive.
4. If one nods fails, it does not affect the rest of the network.
Disadvantages
1. It only supports small number of computers.
2. The network speed slows down as the number of computers increases.
3. A cable break can disable the entire network.
02. Star Topology
All computers in star topology are connected with central device called hub or switch. Star topology is mostly used in client-server networks.
Working of Star Network
The sending computer sends the data to the central device. The central device sends data to the receiving computer. Each computer in star network communicates with a central device.
Advantages
1. It is easy to maintain and modify network.
2. Adding or removing computers can be done without disturbing the network.
3. Finding faults becomes very simple.
4. Single computer failure does not bring down the whole network.
5. It is more flexible than other topologies.
Disadvantages
1. If central hub fails, the entire network breaks down.
2. It requires a large length of cable to connect computers.
3. It is more expensive.
03. Ring Topology
In ring topology, each computer is connected to the next computer with the last one connected to the first. Thus, a ring of computers id formed.
Working of Ring Network
Every computer is connected to next computer in a ring. Each computer receives message from the previous computer and transmits it to the next computer. The message flows in one direction. The message is passed around the ring until it reaches the correct destination computer.
Advantages
1. It is less expensive than star topology.
2. Every computer has equal access to the network.
Disadvantages
1. Failure of one computer in the ring can affect the whole netwok.
2. It is difficult to troubleshoot.
3. Adding or removing computers affects the whole network.
04. Tree Topology
A tree topology combines the characteristics of bus and star topologies. It consists of different groups of computers attached in star topology. The groups are then connected to a bus backbone cable. Tree topology is used for the expensive of an existing network.
Advantages
1. It provides point-to-point wiring for individual segments.
2. It is supported by several hardware and software vendors.
Disadvantages
1. Overall length of each segment is limited by the type of cabling used.
2. The entire network goes down if the backbone line breaks.
3. It is more difficult to configure and wire than other topologies.
05. Mesh Topology
In a mesh topology, every device in the network is physically connected to every device in the network. A message can be sent on different possible paths from source destination. Mesh topology provides improved performance and reliability. Mesh network are not used much in local area networks. It is mostly used in wide area networks.
Advantages
1. If one device on a mesh network fails, the network can still function.
2. Its performance is not affected with heavy load of data transmission.
3. It is easy to troubleshoot.
Disadvantages
1. A full mesh network can be very expensive.
2. It is difficult to install and reconfigure.
