Basics of networking

These are the basic topologies that are the basis for building extended star and mesh topologies in large networks.

Physical bus topology

The bus topology is characterised by the fact that all devices are connected to a common transmission medium. The common transmission medium in this topology is coaxial cable. One disadvantage of this topology is the low throughput (up to 10 Mbps).

This topology was used to build a local area network. The use the word 'was' here is deliberate, because it is no longer commonly used. In addition to its low throughput, it is also very susceptible to network failures. When the coaxial cable breaks, the whole network stops working. The undoubted advantage of using this topology is the low cost of implementation, as there is no need for hundreds of metres of cable or any intermediate equipment.

Physical topology of the ring

In a ring topology, each device is connected to its two neighbours, forming a closed circle. As with the bus topology, this design does not use a large number of cables and additional equipment.

In addition, various transmission media can be used, from coaxial cable to copper twisted pair to fibre optic cable. The disadvantage of this topology is that the interruption of the medium or the failure of one of the computers can disrupt the entire network. To prevent this, so-called double rings are used, i.e. doubling the number of connections between devices. Such a topology is then called double ring topology.

Physical topology of stars

In a star topology, devices are connected to a central point, the access point to the network. In the past, at this point a hub was used, but now a switch is used. It is the most common topology in local area networks because it is easy to design, build and scale, fault-tolerant and easy to manage.

Another advantage is that it can be built using a variety of transmission media, such as twisted-pair copper, fibre-optic cable or radio waves (WLAN). However, a significant disadvantage can be the cost of construction, as additional equipment (switches) and many metres of cable are required.