Network of Topology

The Concept of Topology

In communication networks, a topology is a usually schematic description of the arrangement of a network, including its nodes and connecting lines. There are two ways of defining network geometry: the physical topology and the logical (or signal) topology.

The physical topology of a network is the actual geometric layout of workstations. There are several common physical topologies, as described below and as shown in the illustration

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The Three Topology (Star, Ring and Bus)

Some common network topologies include star, ring, and bus configurations :
Here is some explanation of the three topology :

• Star - One central note is connected to each of the other nodes on a network. Similar to a hub connected to the spokes in a wheel.

• Ring - Each node is connected to exactly two other nodes, forming a ring. Can be visualized as a circular configuration. Requires at least three nodes.

• Bus - Each node is connected to a central bus that runs along the entire network. All information transmitted across the bus can be received by any system in the network.

 

The Advantages and Disadvantages of all Topologies 

Every topologies has it owns advantages and disadvantages. Here i'm going to explain each of the advantages of each topologies :

 STAR :

• Advantages :
  ▸ Due to its centralized nature, the topology offers simplicity of operation.
  ▸ It also achieves isolation of each device in the network.
  ▸ Adding or removing network nodes is easy, and can be done without affecting the entire network.
  ▸ Due to the centralized nature, it is easy to detect faults in the network devices.
  ▸ As the analysis of traffic is easy, the topology poses lesser security risk.
  ▸ Data packets do not have to pass through many nodes, like in the case of a ring network. Thus, with the use of a high-capacity central hub, traffic load can be handled at fairly decent speeds.

•  Disadvantages :

 ▸ Network operation depends on the functioning of the central hub. Hence, central hub failure leads to failure of the entire network
▸ Also, the number of nodes that can be added, depends on the capacity of the central hub.
▸ The setup cost is quite high

 RING :

• Advantages : 
• ▸ The data being transmitted between two nodes passes through all the intermediate nodes. A central server is not required for the management of this topology.
  ▸ The traffic is unidirectional and the data transmission is high-speed.
  ▸ In comparison to a bus, a ring is better at handling load.
  ▸ The adding or removing of network nodes is easy, as the process requires changing only two connections.
  ▸ The configuration makes it easy to identify faults in network nodes.
  ▸ In this topology, each node has the opportunity to transmit data. Thus, it is a very organized network topology.
  ▸ It is less costly than a star topology.

• Disadvantages :

  ▸ The failure of a single node in the network can cause the entire network to fail.
  ▸ The movement or changes made to network nodes affect the entire network's performance.
  ▸ Data sent from one node to another has to pass through all the intermediate nodes. This makes the transmission slower in comparison to that in a star topology. The transmission speed drops with an increase in the number of nodes.
  ▸ There is heavy dependency on the wire connecting the network nodes in the ring.

 BUS  

• Advantages :
  
  ▸ It is easy to set up, handle, and implement.
  ▸ It is best-suited for small networks.
  ▸ It costs very less.
• Disadvantages :
  
  ▸ The cable length is limited. This limits the number of network nodes that can be connected.
  ▸ This network topology can perform well only for a limited number of nodes. When the number of devices connected to the bus increases, the efficiency decreases.
  ▸ It is suitable for networks with low traffic. High traffic increases load on the bus, and the network efficiency drops.
  ▸ It is heavily dependent on the central bus. A fault in the bus leads to network failure.
  ▸ It is not easy to isolate faults in the network nodes.
  ▸ Each device on the network "sees" all the data being transmitted, thus posing a security risk.
  
  
  
  

  How to understand about network topologies in the easiest way?