What is bandwidth?

Data in a tunnel for analytics
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Knowing what bandwidth is and how to measure it is still not universal knowledge, even though the internet plays a more important role in all our lives than ever before.

The term is used to refer to the maximum figure of data that can be sent via a network connection over a fixed period and is typically recorded per second.

Bandwidth only covers the capacity of a network, unlike latency which refers to delay from point to point as information traverses a network.

Over time, network bandwidth has increased considerably. Having begun being measured in bits per second, it is often now measured in megabits or gigabits per second.

What is bandwidth and why is it important?

Think of bandwidth as water flowing through a pipe. Depending on the width of the pipe - which stands in for bandwidth in this scenario - it would take more or less time to drain a reservoir through it.

Increasing the speed at which the water was put into the pipe would only go so far, as there would be an upper limit for how much it could physically contain at any given time.

Internet speed and bandwidth are still connected. If your bandwidth is very low, your network might experience bottlenecks that prevent important applications from working altogether.

Those who have had to download important files over a shared connection while another co-worker uploads a large amount of data may will know just how disruptive this can be.

How do you measure bandwidth?

Measuring bandwidth may seem daunting, with terms like ‘Mbits/sec’ and ‘Gbits/sec’ potentially causing confusion. However, these simply refer to the ‘bits per second’ for your connection, measured either in megabits (one million bits) or gigabits (one billion bits)

Your internet service provider (ISP) will have provided you with your bandwidth in your contract. A speed testing tool will provide a number for the ‘throughput’ of your network - the actual figure of data transmitted over your network over a period.

There are a number of free tools for measuring this online, including Ookla’s Speedtest.net, the speed tests available on most ISP websites, or Google’s own that can be accessed by searching the term “speed test”.

There are a number of more detailed ways to measure both network throughput and bandwidth, listed in our measuring bandwidth guide.

In the UK, the current average broadband speed is 65.3 Mbits/sec, according to Ofcom, a helpful bandwidth for those in hybrid work. With a strong home connection, remote employees can confidently transfer large amounts of data, or take important video calls.

Those living in rural communities across the UK still struggle with connectivity and, as a result, are more likely to have poor bandwidth than those living in built-up areas.

For businesses, it's important to assess how much bandwidth you will need to perform your daily operations. That not only involves figuring out how many employees will be accessing the network at once but also taking into account the bandwidth requirements for any applications they will be using.


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Another thing to consider is the fact that the data has to flow through several connections to reach you, and your connection to your ISP might impact your bandwidth speeds.

It's also important to remember that even if you have plenty of bandwidth available, you will need to reduce the network's latency in order to improve the speed at which data packets move across the network. This is particularly important for applications and services that require high data transfer rates beyond what a normal network connection can provide.

Depending on your provider, where your business operates, and what kind of internet service you pay for, you might have a different internet connection. Here are the possibilities:

FTTP (fiber to the premises) - This is easily the fastest kind of service and can deliver up to gigabit broadband. It is especially useful for office buildings and sees fiber optic cables run right up to your property, supporting higher capacity lines direct to your business infrastructure.

Ofcom’s Connected Nations 2022 report [PDF] stated that 42% of UK premises now have access to FTTP broadband.

FTTC (fiber to the cabinet) - By far the most common connection in the UK, FTTC sees internet service providers (ISPs) link your home to a cabinet on the street with copper wires - much slower than the fiber-optic cables connecting the cabinet to a telephone exchange.

FTTN (fiber to the node) - A node is just further away than a cabinet (miles further, sometimes), potentially slowing your internet connection even more.

If slow bandwidth becomes a more common occurrence, you might want to check with your broadband provider. 

Bandwidth glossary

Although bandwidth may be fairly straightforward, it's always useful to read up on the most common terms used in this field. Here's a selection of them:

Data packet: A unit of data made into a single package that travels along a network path. It's a small amount of data sent over a network and, just like a real-life package, contains a source and destination, as well as the content being transferred.

Broadband: This is wide bandwidth data transmission which transports multiple signals and traffic types. It provides high-speed internet access through multiple mediums like coaxial cable, optical fibre, radio, or twisted pair.

ISP: This stands for internet service provider, normally referring to the company that is providing you with access to the internet.

Latency: This is the time it takes one data packet to travel from its source to its destination, or in other words, the delay between a user's action and the response from a network.

Dale Walker

Dale Walker is the Managing Editor of ITPro, and its sibling sites CloudPro and ChannelPro. Dale has a keen interest in IT regulations, data protection, and cyber security. He spent a number of years reporting for ITPro from numerous domestic and international events, including IBM, Red Hat, Google, and has been a regular reporter for Microsoft's various yearly showcases, including Ignite.