Bandwidth and latency are closely connected.
They depend on one another for optimum network performance. So it’s no wonder why it could be easy to confuse them.
Let’s take a look at what each of these terms really means, and how they work together.
What is Bandwidth?
Bandwidth tells you how much data your network could theoretically handle.
It is the maximum transfer capacity available for you to use. It is usually measured in bits (bps), megabits (Mbps), or gigabits (Gbps) per second [1].
So, what does this mean? Let’s take a look at a simple example.
For example, the internet “speed” advertised by your internet service provider is in fact your bandwidth.
If they provide you with a 500 Mpbs link, that is the most amount of data you will be able to send at any given moment.
If at a later day you decide to upgrade to a better plan, you are upgrading your bandwidth, not your speed.
Sure, you’ll notice that websites load faster and downloads are quicker. But this just means that your network is now able to handle more data in the same amount of time.
This gives the impression of a faster connection. But the speed at which said data is traveling is still the same.
What is Latency?
In networking, latency refers to the amount of time it takes for your data to be sent to its intended destination. It’s also referred to as the delay in moving data between two clients [2].
Latency is usually measured in milliseconds (ms). And the lower it is, the better.
Let’s look at a real-world scenario of how latency can affect your network and browsing experience.
If you are participating in a video call, your video feed needs to be sent to the other party in real time and vice versa.
With excellent latency (a low number), your video feed is sent almost instantly. This means the other participant will see and hear you fluidly, without interruptions.
But if latency is too high, your video feed will take too long to get to the other side. Causing delays in the video feed and long pauses in the conversation between participants. Not a good experience.
Another clear example is online gaming. Since you are playing in real-time, it’s vital that your inputs reach their destination as fast as possible.
If latency is too high, other players might have moved on to something else while your screen still shows outdated data.
The Difference between Bandwidth and Latency
Now that we know what each of these terms really means, it’s clear they are different.
Bandwidth measures size (how much data you can send). And latency measures speed (how fast the data travels).
In short, they depend on one another.
It’s no good to have a massive amount of bandwidth if your latency is through the roof. Data will travel at slow speeds no matter what in this case.
On the other hand, there’s not much use for low latency if your bandwidth is too small. Even if it takes half a millisecond to reach the other side, it can only carry as much data as your bandwidth allows.
What Affects Bandwidth?
As we determined above, bandwidth at our homes is dictated by our internet service provider. There’s not much we can do to increase it besides paying more for extra bandwidth.
There is one thing to keep in mind though. Your router, especially your wireless router, can limit your bandwidth. Make sure your router can handle your internet service provider’s bandwidth.
Otherwise, you will be paying for bandwidth your device is not physically capable of using.
What Affects Latency?
Unfortunately, finding the cause of high latency is not always easy. As multiple factors can negatively affect it.
Distance
Even though sometimes it doesn’t look like it, data travels physically. Usually in the form of light.
Two nodes close to each other geographically will always have less latency than a node trying to communicate with another one on the other side of the world.
For example, businesses regularly store their data remotely on data centers. The closer this data center is to the office, the less latency it will have.
If the business requests information from the data center thousands of times a day, it would be in their favor to have as low latency as possible.
Network Congestion
When your local network traffic exceeds your bandwidth, data needs to wait to be sent.
This naturally results in increased latency. And the more congested the network is, the higher the latency will be.
Wireless Connections
Wireless signals add an extra layer of delay. Your data needs to be sent through the air to your wireless router.
Avoiding walls, doors, and other obstacles. Once it gets to your router, it will travel to its intended destination. This extra step unavoidably increases latency.
You can “clean” your environment as much as possible by removing obstacles and interference in order to decrease latency.
But a wireless connection will always have more latency than a wired one because of the extra travel needed.
Wrap Up
Bandwidth and latency are naturally interconnected. You can’t expect to improve one while ignoring the other.
If you want to have a good experience, you must have sufficient bandwidth and low latency.
One or the other alone is no good.
If you want to learn more, check out our article on Bandwidth vs. Throughput.
