Network topology refers to the physical configuration of a set of interconnected computing devices. It details not just how devices on the network are connected but also how data moves from one node to another. The most common types of topologies are star, bus, ring, dual ring, tree, mesh and hybrid topology.
There’s no one-size-fits-all when it comes to network topology. What is perfect for one organization may be woefully inadequate in another. The following are the key factors you should pay attention to when choosing a network topology.
A rule of thumb is to never make technology procurement decisions based on price alone. There’s no denying though that you can only cut your coat according to your cloth. If a topology is unaffordable, it’s off the table no matter how perfectly suited it might be for your situation.
In any case, irrespective of what your preferred topology is, there’ll almost always be a lower-priced alternative that’s nearly as effective. On pricing matters, bus and ring topologies are quite cost-effective while star, mesh, tree and hybrid topologies are expensive.
2. Hardware Resources
Certain network topologies work best with certain hardware. And vise-versa. So before you make a decision on the topology to adopt, perform an inventory of your current hardware. You may also already have the hardware needed to implement a certain type of topology. So as opposed to buying everything from scratch, such existing resources give you a head start.
For instance, you may have hardware limitations such as the length of the network cable. In that case, you’d go for a topology that requires the least amount of cable for connecting nodes. Bus and star topologies perform pretty well in this regard.
3. Ease of Implementation
If you’ll contract a third party to install and/or maintain your network, then the complexity of the network topology you choose is perhaps a non-issue. A competent networking professional will have the education and experience needed to comprehend what each topology entails and implement it accordingly.
However, if you expect to leave network implementation in the hands of novices or individuals without the requisite IT training, then the ease of the topology should be a major factor in your choice. In this case, the bus and star topologies score pretty well. The mesh, tree and hybrid, on the other hand, are complex and difficult for a layman to install or understand.
4. Size of Network
How many devices are going to be on your network? How geographically dispersed are they? How far from the ‘center’ is the furthest device? Some topologies are inadequate or expensive when applied to large networks. A topology that works perfectly for a 5-device network may prove a disaster when applied to a 10,000-device organization. Network topology mapping is considered an absolute necessity in enterprise-level networks since it helps to locate and troubleshoot issues by identifying which nodes are working from the network map and delivering data on the actual status of devices.
Part of the inventorying process we referred to in point 2 should include determining the total number of devices to be interconnected. Armed with this information, you can choose the topology that would best serve the purpose. The tree topology works well with large networks. The bus topology is best suited for small organizations.
When it comes to reliability, network topologies aren’t created equal. If you are looking for high reliability because you are in an industry where even brief downtime and delays are frowned upon (e.g. banking), then network reliability is a fundamental consideration. Choose the topology that delivers the highest reliability.
Ring topology performs pretty well under heavy loads but is prone to a single point of failure. Star topology doesn’t depend on any node but the network will collapse if the hub fails. Mesh and hybrid topologies score highest on the reliability front.
6. Future Expansion
If you expect your organization to grow in size in the medium to long-term, opt for a network topology that’s readily scalable. Identify the topology that’s easy to add new nodes to, without negatively affecting network performance or the user experience of other devices on the network.
The tree topology is perhaps the most compatible with future expansion requirements as it’s fairly easy to extend or shrink the network. The bus topology is also easy to expand but only to a certain extent which is why it would only work for small networks.
Choosing a network topology is one of the most important decisions you’ll make for your technology infrastructure and will have far-reaching ramifications over the long-term. A wrong choice can prove to be an expensive mistake. It’s a decision that requires careful thought in order to get it right from the start.