Category Archives: Introduction to Networking

Star Topology


DEFINITION

  • Star Topology is a form of computer connection or a geometric representation of the relation of more than one computer which the device has a dedicated point-to-point link only to a central controller (HUB ).
  • The devices are not linked to one another directly, but it uses a controller for sending the data. It means if a device wants to send a data, it will be sent to a controller or hub which then relays the data to the other connected devices.
Star Topology

          

ADVANTAGES OF STAR TOPOLOGY

  1. Less expensive than mesh topology.
  2. Flexible.
  3. The assemblies station is very easy without any interruption to another network.
  4. Only has one controller ( central controller/HUB).
  5. Easy to be detected.
  6. If one link fails, only that link is affected. So, it will not affect to another link.
  7. Far less cable than mesh topology.

THE DISADVANTAGES OF STAR TOPOLOGY

  1. Need a specific handling.
  2. The central controller(HUB) become a critical element. If he HUB is down, the whole system is dead.

Reference

Behrouz A. Forouzan. “Data Communication and Networking” . 4th Edition

 

BUS TOPOLOGY


Definition

Network cabling scheme in which all computers and devices (nodes) are connected to a single cable so that all nodes receive the same message at the same time.

Bus Topology

            (Source : http://www.technologyuk.net)

Advantages

  1. Include ease of installation
  2. Backbone cable can be laid along the most efficient path
  3. Uses less cabling than mesh or star topologies
  4. Redundancy is eliminated
  5. It is easy to set-up and extend bus network
  6. Costs very less
  7. Linear bus network is mostly used in small network

Disadvantage

  1. Difficult reconnection and fault isolation
  2. Difficult to add new devices
  3. There is a limit on central cable length and number of nodes that can be connected
  4. Proper termination is required to dump signals. Use of terminators is must
  5. Maintenance costs can get higher with time
  6. Efficiency of bus network reduces, as the number of devices connected to it increases
  7. It is not suitable for networks with heavy traffic
  8. Security is very low because all the computers receive the sent signal from the source

References