How to check bandwidth usage can be one of those exasperating problems that don’t always reveal themselves right away. Because what’s hogging your bandwidth might not be apparent just by looking at basic statistics. The good news is, many of these problems can be located and dealt with before they cause you all kinds of stress.

Let’s talk about why how to check bandwidth usage is so important, how to find hogs, and what to do to optimize your network for future use once you get them under control.

Why bandwidth use matters

Bandwidth use matters because it affects not only the performance of your network, but can cost your company money in expensive bandwidth that’s being over-utilized. It can also create serious productivity problems for the rest of your users. It can also affect how certain time-and-delay-sensitive traffic are performed, such as voice and video, as well as applications that require frequent access to the mouse or keyboard.

Tracking down the sources can be tricky. For example, a network I worked on years ago noticed there was an increasing number of dropped phone calls happening on their system. After further investigation, we found that the phones themselves were all up to snuff, no hardware issues and no firmware or software issues. But the problem persisted.

We checked and double-checked the QoS (quality of service) settings, and everything seemed to be working correctly. Eventually, we found the problem when we noticed something strange. There seemed to be an excessive about of bandwidth being utilized on the voice VLAN that we had set up for all telephones. And there was the problem: One device, mistakenly added to the voice VLAN, was using a tonne of video streaming traffic. Since the voice VLAN had traffic priority (most office settings will give VoIP traffic priority as a best practice), it was gobbling up all the bandwidth it could! Voice traffic does not necessarily use a lot of bandwidth, but video streaming does! This was the problem. Once the video device was moved to a different VLAN, it cleared up the problem.

Here’s a few other tips on how to troubleshoot a slow network.

busy traffic
Source: Bradyn Trollip/Unsplash

Your bandwidth usage could be affecting your device or user experience

Knowing different techniques on how to check bandwidth usage, like a checklist to run through, is important. When you know what’s causing network congestion, and how to check bandwidth usage, you’re halfway to solving the problem. Let’s look at a few examples.

Overall network utilization

This is a pretty obvious sign of an issue. Excessive bandwidth usage will affect overall utilization, causing the network to slow down, giving everyone a poor user experience regardless of where they are on the network. Chances are you’ll hear from end users fairly quickly when the overall network speed starts to drop off.

Security issues

There’s all manner of security features that can be affected by improper bandwidth usage. A big concern is the effect it can have on the performance of security appliances such as firewalls and IDS/IPS devices. Without access to bandwidth, they may not operate efficiently enough to catch issues as soon as they see them.

Bandwidth hogs can also be a sign of malicious attacks. An important and common security issue is the denial of service (DoS) attack. This attack purposely floods a network with excessive packets to the point of where it completely stops working. Clearly, this is an extreme version of hogging your bandwidth, but the end result is the same: reduced bandwidth capacity that affects your end users and devices.

Customer service

Many online applications are built specifically to serve customers. A lack of bandwidth could mean your customer service agents are unable to make critical KPIs, like addressing X many customers per hour, or customer service applications for your online customers becoming unavailable. These types of problems can literally drive your customers away from your business and towards a competitor.

Video conferencing problems

In the past few years, video conferencing has gone from a rarely-used feature of convenience to a must-have for almost every company. As you know, video conferencing is hard on a network. It can be one of the most demanding things your corporate network, and definitely your home network, will deal with. The high traffic rate going in and out (full duplex), and the need to maintain extremely low latency requires near perfect performance. Anything less can lead to instability, drop-outs, or no connection at all. If a mystery device or service suddenly removes capacity that’s needed for your Zoom meeting, your productivity is going to grind to a halt until it can be restored.

How to tell what’s hogging your bandwidth

First thing, you have to be able to locate and pinpoint what’s using your bandwidth, and where it’s lagging. Start with a set of tools to accomplish this. Assuming we are referring to enterprise-class networking equipment, these tools are SNMP (simple network management protocol), FLOW protocols, device statistics, and a great management console to bring it all together in a way that makes actionable insights possible.

Let’s take a second to look at each of these tools a little closer.


SNMP is a set of protocols for capturing and measuring the statistics and performance of your network devices. You’ll want to enable it on the devices you want to monitor. Then, you’ll need a network management console that can collect, organize, store, and manage this data (see below).

Flow Protocols

Flow protocols go a step further from SNMP, looking at actual traffic flow from point A to point B, determining performance, speed, delay, number of errors, etc. This is an excellent way to see who is using your bandwidth. Flow “flavors” include sFLOW, Netflow, and Jflow.

Device statistics

Device statistics are going to show you a lot of raw data on different parts of a switch or router, like top talkers, ports utilization, errors, and dropped packets. Taken by themselves, these statistics can be confusing, but a good management console is going to help you sort this out and display the results in ways that make sense.

Packet sniffers

Packet sniffers are devices attached to a specific port on a switch or router to sniff out low-level network or hardware problems. Normally, these are attached to a switch port, and then you mirror the port you would like to sniff out. Packet sniffers are often used by experienced network managers to locate particularly deep or complex problems.

Management console

Last, but not least, you’ll want an effective management console to not only collect and track this information, but to be able to analyze the data and make it useable. A console with good network traffic monitoring software is key. Once you put all of these pieces together, you’ll start to see who’s the hog at the trough. And many times, it’ll surprise you.

The key thing to understand about your management console is that it needs to support a variety of technologies. It also needs to be able to collect all types of statistics, store them, and correlate them. This is a tremendous amount of data. And to sort through all of this data can be difficult and time-consuming. So having effective purpose-built applications that are designed for how to check bandwidth usage is very important.

How to maintain sufficient bandwidth on your device

To maintain sufficient bandwidth on your devices, you’ll need to do a few things on an ongoing basis. These activities should be performed regularly and follow best practices outlined by the vendors of the specific pieces of hardware, as well as your own company performance goals.

Follow a set of consistent statistics

You should have your management console configured to track and follow thresholds over time. It should be watching these statistics with pre-configured alerts to report changes outside your established limits, such as excessive dropped packets, flows that are out of the baseline, or if top talkers change position repeatedly.

Bonus tip: low priority servers
Low priority servers, like email of Syslog servers, should not get too much share of overall bandwidth. If they do, they can quickly hog it from other more important servers or applications, which will start to be felt by the end user.

Establish a baseline

You should know what your network looks like—what’s normal and what’s not. Understand your traffic flows and baseline them over time. Through an entire business cycle, a month or a quarter, if possible. Once you know what is normal, ask yourself, “is everything performing correctly”? If it is, then you’ve got a good baseline. You’re ready to look for anomalous behavior.

Monitoring tools

Now that you know how to check bandwidth usage you can start to monitor your network from an informed place. Your network monitoring console will be able to keep track of where your devices are, what their performance is supposed to be, and how well you are performing throughout your business cycle.

Your monitoring tools can have many built-in alerts ready to go to make this easy and quick. As well, the ability to look at performance in real-time can be a tremendous help when look for that special something or someone that’s hogging your data.

Also, take advantage of the ability to customize alerts after they are up and running. This may take a bit of reviewing over time to establish the levels you want, but as you gain greater knowledge of your network, this will become much more efficient.

Review and revise how you check bandwidth usage

I always recommend that once you have completed a full business cycle, have good baselines set up, and your management console is fully up and running, you go back and review and revise your setup. By this time, you should instinctually know how to check bandwidth usage. Check your statistics again. Check it on certain key dates—like quarter over quarter and end of the year. During an upgrade or change in ISP vendor. Before and after the pandemic. All of these are opportunities to look at what you had before and reevaluate your performance. Did any of your flow patterns change? Who are the top talkers now? How are the packet loss statistics? Was anything new added without your knowledge? What about multimedia traffic? Did it change? How did it change? Do you need to capture packets to see if they are malformed?

This is a key step in getting really familiar with every nook and cranny of your network. Make the review and revise process part of an annual or quarterly process to ensure good, strong maintenance of the bandwidth on your network.

If you’re in need of complete visibility and control of your network infrastructure, check out Auvik’s cloud based network management. Try it free for 14 days.

  1. Femi Avatar

    So informative

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