Which network topology is not robust

Types of network topology

The arrangement of a network, which consists of nodes and connecting lines via transmitter and receiver, is called Referred to as network topology. The different network topologies are:
 

a) Mesh topology:
In the mesh topology, each device is connected to another device via a specific channel.

Advantages of this topology:

  • It is robust.
  • Errors are easily diagnosed. The data is reliable as the data is transferred between devices via dedicated channels or links.
  • Provides security and privacy.

Problems with this topology:

  • Installation and configuration is difficult.
  • The cost of the cables is high because extensive wiring is required, so it is suitable for a smaller number of devices.
  • Maintenance costs are high.

b) Star topology:
In the star topology, all devices are connected to a single hub via a cable. This hub is the central node and all other nodes are connected to the central node. The hub can be passive in nature, i.e. a non-intelligent hub such as broadcasting devices, but at the same time the hub can also be intelligent, known as an active hub. Active hubs have repeaters in them.

Advantages of this topology:

  • If N devices are connected together in the star topology, then the number of cables required to connect is N. So it is easy to set up.
  • Each device only needs 1 port, i. H. for connection to the hub.

Problems with this topology:

  • If the concentrator (hub) on which the entire topology is based fails, the entire system crashes.
  • Installation costs are high.
  • The performance is based on the individual concentrator; H. the hub.

c) Bus topology:
The bus topology is a type of network in which each computer and network device is connected by a single cable. It transfers the data from one end to the other in one direction. There is no bidirectional function in the bus topology. It is a multipoint connection and a non-robust topology, because if the backbone fails, the topology collapses.

Advantages of this topology:

  • If N devices are interconnected in the bus topology, then the number of cables required to interconnect them is 1? what is known as the backbone cable and N stubs are required.
  • The cost of the cable is lower compared to other topologies, but it is used to build small networks.

Problems with this topology:

  • If the common cable fails, the entire system crashes.
  • When the network traffic is high, there are more collisions in the network. To avoid this, various protocols are used in the MAC layer, such as Pure Aloha, Slotted Aloha, CSMA / CD, etc.

d) Ring topology:
In this topology, a ring is formed that connects devices with exactly two neighboring devices.

For a ring topology with a large number of nodes, a number of repeaters are used because if someone wants to send data to the last node in the ring topology with 100 nodes, then the data has to pass 99 nodes to reach the 100th node. To avoid data loss, repeaters are used in the network.

The transmission is unidirectional, but can be made bidirectional by having 2 connections between each network node, this is known as a dual ring topology.

 

Advantages of this topology:

  • The possibility of collisions is minimal with this type of topology.
  • Inexpensive to install and expand.

Problems with this topology:

  • Debugging is difficult in this topology.
  • Adding intermediate stations or removing stations can disrupt the entire topology.

e) tree topology :
? This topology is the variant of the star topology. This topology has a hierarchical data flow.

Advantages of this topology:

  • More devices can be connected to a single central hub, increasing the distance the signal must travel to get to the devices.
  • It allows the network to isolate itself and also to prioritize it from different computers.

Problems with this topology:

  • If the central hub fails, the entire system fails.
  • The cost is high because of the wiring.