Networking is a very important topic in computer science, and it allows computers to communicate the way information is transferred across clients and servers, and used to share information worldwide. To organize the way computers are interconnected and the way and flow computers communicate is defined by the topology a network is organized. Network topology is defined as the way the nodes are placed and interconnected with each other. (Technopedia, 2015).
This article will introduce and compare two of the most common topologies used in computer networking.
Bus Topology → Organized with all the nodes connected sequentially to the same transmission line. To illustrate it, just imagine a single cable where all the computers are connected. The weakness at this point is that considering all the communication flows in only one channel, a failure may damage all the networking activity.
Star Topology → All the nodes are connected to one distributor device (hub or switch, for instance). Failures may not affect all the computers if it happens on the nodes, however it may affect all the nodes if this happen in a central/distributor device.
Figure 2 Star topology
Deadlock is a concept in computing which is related to a computer problem which does not allow a system to operate in a regular manner. TechTarget defines it as “A deadlock is a situation in which two computer programs sharing the same resource are effectively preventing each other from accessing the resource, resulting in both programs ceasing to function.”. One example of deadlock is as follows:
Table 1 Example of Deadlock
Deadlocks in the Bus topology may happen as each network segment is, therefore, a collision domain. Deadlocks in the bus topology may happen because the way data is transferred using the same cable simultaneously as Concept Drawn says “Each network segment is, therefore, a collision domain. In order for nodes to transmit on the same cable simultaneously, they use a media access control technology such as carrier sense multiple access (CSMA) or a bus master” (Concept Drawn, 2015).
ADVANTAGES OF THE BUS TOPOLOGY
Bus topology may work in very small networks which does not need a lot of resources and equipments, what makes a networking solution cheaper;
It requires less cable;
Easiest network topology to be implemented.
DISADVANTAGES OF THE BUS TOPOLOGY
Difficult to identify problems on the network;
Hard to identify individual issues;
Slow when connected with many devices;
Not recommended for large networks;
ADVANTAGES OF THE STAR TOPOLOGY
Easy to add computers and very extensible;
In the case a computer fails, others continue communication not being affected.
DISADVANTAGES OF THE STAR TOPOLOGY
May require expensive equipment;
If the centralized device fails all the network is impacted.
It is hard to say the right recipe for a network, what can be for sure recommended is based on the communication requirements, budget allowed to implement and expectations it may attend. In the case of a low budget and a few computers, imagine how cost effective would be to implement a bus topology and in the case of more financial resources and a high quantity of computers, it would be for sure a best strategy to use the star topology.
Technopedia. 2016. Network Topology. [ONLINE] Available at: https://www.techopedia.com/definition/5538/network-topology. [Accessed 15 January 16].
TechTarget. 2016. Definition of Deadlock. [ONLINE] Available at: http://whatis.techtarget.com/definition/deadlock. [Accessed 15 January 16].
ConceptDrawn. 2016. Bus network topology diagram. [ONLINE] Available at: https://conceptdraw.com/a878c3/preview/640. [Accessed 15 January 16].