NAME: USAMA NUMAN
ROLL NO: 543-BH-2018
: NETWORK TOPOLOGY AND ITS TYPES:
The way in which a number of computers are connected together in a network is called network topology. It is physical layout or arrangement of computer in a network.
There are five basic topology for connecting computers in a network.
1. Bus topology.
2. Star topology.
3. Ring topology.
4. Tree topology.
5. Mesh topology.
1. Bus topology:
In bus topology, the computers or network nodes are connected to a common communication medium, called the backbone.
Working of bus topology:
The sending computer attaches the address of the destination computer with the data. It then sends this data to the bus. All computers connected to the bus receive the data but only that computer accepts the data whose adders matches the address attached with the data.
In this topology only one computer can send data at a time.
Therefore, the speed of a network reduces as the number of computers attached to the bus increases.
also be used to extend th not affect the rest of the network.
bus. A cable-break, fault in any one computer or a loose connection may cause breakdown of the whole network.
2. Ring topology:
In ring topology, each computer or node is connected to the next computer and the last computer is connected to the first. Thus, a ring of computer is formed.
Working of ring topology:
Every computer receives message from the previous computer and transmits it to the next computer till the destination computer receive the message. Since each computer re-transmits what it receives, signal-loss does not occur.
3. Star topology:
In star topology, all computers or nodes are directly connected to a central device. The central device that connects the nodes is called hub.
Working of star topology:
Each computer on a star network communicates with the cable hub. The hub then sends data to the destination computer.
central hub and a node is relatively low, low specification twisted pair can be used to connect the nodes to the central hub.
4: tree topology:
A tree topology combines characteristics of linear bus and star topologies, it consists of groups of star configured work stations connected to a linear bus. The bus works as a backbone cable for the network.
Supported by several hardware and software manufactures.
difficult to configure and wire than other topology.
5. Mesh topology:
In mesh topology, each device is physically connected to every other device on the network. Thus messages sent on a mesh network can take
any of several possible path from source of destination. Each device is physically connected to every other device on the network. This increase performance and reliability. However the complexity and difficulty of creating a mesh network increases as a number of nodes on the network increases For example, a three or four node mesh network is relatively easy to create, where as it is impractical to set up a mesh network of 50 nodes. Mesh network are not used much in local area networks(LANs) but are used in wide area networks (WANs) where reliability is important and the number of devices being connected together is fairly small,
6 Point to point
The simplest topology is a permanent link between two endpoints. Switched point-to-point topologies are the basic model of conventional telephony. The value of a permanent point-to-point network is the value of guaranteed, or nearly so, communications between the two endpoints. The value of an on-demand point-to-point connection is proportional to the number of potential pairs of subscribers, and has been expressed as Metcalfe’s Law.
Advantages of Point to Point Topology:
1. Highest Bandwidth because there is only two nodes having entire bandwidth of a link
2. Very fast compared to other network topologies because it can access only two nodes.
3. Very simple connectivity
4. It provides low Latency
5. Easy to handle and maintain
6. Node Can be Replaced in few seconds
Disadvantages of Point to Point Topology:
1. This topology is only used for small areas where nodes are closely located.
2. The entire network depends on the common channel in case of link broken entire network will become dead.
3. There is another major drawback of this topology there are only two nodes if any of the node stops working, data cannot be transfer across the network.
A hybrid topology is a type of network topologythat uses two or more differing network topologies. These topologies include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology.
1) Reliable : Unlike other networks, fault detection and troubleshooting is easy in this type of topology. The part in which fault is detected can be isolated from the rest of network and required corrective measures can be taken, WITHOUT affecting the functioning of rest of the network.
2) Scalable: Its easy to increase the size of network by adding new components, without disturbing existing architecture.
3) Flexible: Hybrid Network can be designed according to the requirements of the organization and by optimizing the available resources
1) Complexity of Design: One of the biggest drawback of hybrid topology is its design. Its not easy to design this type of architecture and its a tough job for designers. Configuration and installation process needs to be very efficient. 2) Costly Hub: The hubs used to connect two distinct networks, are very expensive. These hubs are different from usual hubs as they need to be intelligent enough to work with different architectures and should be function even if a part of network is down.
3) Costly Infrastructure: As hybrid architectures are usually larger in scale, they require a lot of cables, cooling systems, sophisticate network devices, etc.