It is easy to take networks for granted. Devices get added and via some technological magic, they all seem to be able to talk together quite happily. Behind that magic, however, are design decisions that need to be made to maximise performance, availability, and service levels. What type of layout or topology should a network have? How can you grow or change a network to meet changing business needs? What happens if you suspect a network is no longer working as well as it could? Let’s take a look.
What is network topology?
Network topology refers to the layout of routers, switches, devices, and connections on a network, both physically and logically. This can be represented in a network topology diagram, with devices shown as nodes, and communication connections as links.
Physical network topology refers to the layout of physical devices, for instance, routers, wires, cables, and so forth. Logical network topology describes the way the nodes talk to each other, and how data flows, regardless of the physical connections. Effective network management requires a good understanding of both the physical and logical topology of a network.
Why Is Network Topology Important?
The topology of a network has a direct impact on its performance and functionality. A well designed and managed network can help decrease operational and maintenance expenses by increasing energy and data efficiency. A well-designed network will also help reduce potential cyber risks. It will also have redundancy and self healing capabilities. Once in place, network topology diagrams are useful for diagnosing network connectivity issues, evaluating network slowdowns, and troubleshooting issues in general.
Common Types of Network Topology
There is no single type of network topology, or indeed a ‘best’ solution. Each design has pros and cons in terms of functionality, performance, and cost. There are, however, some basic topologies on which networks are based.
Bus Topology
The bus topology, sometimes known as a backbone topology, physically connects every device in a network to a main cable. Each device is connected by a drop cable, which is referred to as line topology. This is an excellent and cost-efficient way to implement a smaller network, with additional nodes simply added through more connections on the bus. Downsides include the vulnerability of the main bus failing, and limitation of being half-duplex. This means data can only be sent in one direction at a time, making it not ideal for high data volume environments.
Star Topology
A star topology has a central node with devices directly connected to it. In a star topology, the devices do not communicate directly with one another. Messages are sent to the central node, which then sends the message to all other systems. The central node acts as both a server and a repeater, with information transmitted from any node on the network passing through the central one to reach its final destination.
Ring Topology
In ring topology, nodes are arranged in a circle, or ring. The data can travel through the ring network in either one or both directions, with each device having exactly two neighbours. Only one station on the network is allowed to transmit data at a time, greatly reducing the risk of packet collisions. This makes ring topologies efficient at transmitting data without errors. A ring topology is vulnerable to failure without proper network management; if one node goes down, it can take the entire network with it. Additionally, the whole network must be temporarily taken offline to reconfigure, add, or remove nodes.
Tree Topology
A combination of a bus and a star network design, a tree topology is one where the devices are connected in groups to form branches, and those connected to form the tree. It is one of the most popular types of network topologies. Tree networks are very easy to scale, with both individual nodes and new branches (rings) being easy to add. The main downside is the single point of failure of the root node, where all the branches join. This more complex design does have a small management overhead too.
Mesh Topology
In a full mesh topology, every node directly connects to every other node using a point-to-point connection. Data transmission occurs through either routing or flooding. Routing ensures the data travels the shortest distance between two points. Flooding sends data packets to all nodes in the network. The mesh structure means there is no single point of failure, making it very resilient, however the high cost of cabling and management means it is only suitable for small or specialist network environments.
Hybrid Topology
As you might have guessed, a hybrid topology is where more than one design has been used to provide the required functionality, performance, and availability. Hybrid topologies offer the most flexibility, especially across larger, multi-purpose networks, however their complexity means more focus on design and management is required.
Which topology Is best for you and your customers?
There is no single topology that works best for everyone. Many businesses end up with a de facto hybrid topology, simply by the way new nodes get added over time, whether to support new users, equipment, or projects. These networks often hide unknown weakness in the area of reliability, security, or performance.
Network mapping software can be used to create a diagram of a given network, from which remedial actions can be taken to remedy a weakness. Given the complexity of larger networks, it is recommended to use a specialist network auditing service, which will fully examine, analyse, and evaluate entire IT infrastructures and systems to identify opportunities for growth, development and potential budget savings. This can be done working with a channel business, ensuring that client satisfaction and continuity is maintained.
How can Smart CT help?
IT surveys, audits and health checks can be complex and time consuming. Smart CT offers a cost-effective way of conducting high-quality audits carried out by experienced and certified engineers. This allows you to easily enhance your service offering without the challenge and cost of maintaining resources with the specialised skills and knowledge required for this task. Smart CT is 100% dedicated to the channel, working with you to provide the best service to your customers.
If you would like to find out more about our network audit and design services, and how we work with the channel, please get in touch.
