What is network congestion and how to fix it?

Vlad Constantinescu
by Vlad Constantinescu
VPN Expert & Privacy Advocate
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  • More and more people use their personal devices to connect to the Internet every day. However, too many devices on the same network can lead to network congestion.
  • Network congestion often solves by itself. However, if the network is poorly managed, it will likely become a frequent problem and lead to other issues such as packet loss or high ping.
  • Check out our guide to learn more about packet loss and how to fix it.
  • Visit our Network & Internet Hub to learn more about proper network management.

Technology advancements have made it possible that more and more people can benefit from an Internet connection every day. However, without proper management, this could lead to various inconveniences.

Imagine networks as cities and Internet-connected devices as citizen-owned cars. Much like cities, if networks aren’t properly managed, upgraded, and even expanded if necessary, they will end up heavily congested.

Network congestion isn’t a simple matter. Actually, it’s one of the most complex challenges that a network administrator could face. Mostly because there’s no magic fix for it other than competent management skills.

Much more so if you’re on one of the receiving ends or one of the causes of said congestion.

If you’re experiencing network congestion and you’re not in any way in charge of managing the network, there’s pretty much nothing you can do, aside from contacting the network administrator.

What is network congestion?

Network congestion is a phenomenon that appears due to a series of factors. Mainly, it is caused by too many devices on a network that isn’t designed to carry that big of a load.

The good news is that network congestion isn’t a permanent issue, or at least it shouldn’t be. Much like rush hour, it occurs every time there are several connected devices that are using network resources at the same time.

It can also occur when there are not too many devices on the network, but some of them put an excessive load on the network or perform actions that use a lot of bandwidth, such as torrenting.

The bottom line is that improper network management could lead to these clogs of sorts. Once some of the devices log off or stop exerting the load on the network, the situation should automatically alleviate for everyone, one bit at a time.

Network congestion is also a lead cause in the following underlying issues:

  • High latency (delay) – on a congested network, the time a packet needs to reach its destination might increase by a large deal
  • Connection timeouts – many services will timeout instead of waiting for the arrival of packets
  • Packet loss – if the network is congested, many packets might not be able to reach their destination and will get dropped

What causes network congestion?

Although you probably painted quite a clear picture in your mind already, there are several key factors that play a role in network congestion. The city traffic analogy is quite appropriate, don’t you think?

With that in mind, let’s take a look at the most common causes of network congestion:

  • Too many devices on the network – if the network can’t handle numerous devices, congestions will most likely occur (imagine a narrow street overflowing with cars).
  • Excessive bandwidth consumption – sometimes, certain users or devices can consume more bandwidth than the average user/device on the network. This can stress the network and its routing devices (routers, switches, cables), which in turn can lead to network congestion.
  • Old, obsolete, outdated hardware – not all of them at once, of course. However, paying for a gigabit plan, and having a network adapter that can handle connections up to 100 MBs can lead to bottlenecks. These, in turn, can affect all the network participants. The same goes for old routers or poor-quality connection cables.
  • Poor subnet management – if you have a large network, you will need to divide it into subnets, for better resource management. However, if the subnets are not sized according to usage trends and resource needs, network congestion might become a problem.
  • Over-subscription – a measure that’s usually adopted for cutting costs, but can lead to the network being forced to handle way more traffic than it’s supposed to (at the same time)
  • Broadcast storms – misconfigured networks with large subnets can be subject to broadcast storms, which can lead to network congestion
  • Devices with constantly high CPU loads – over-using certain devices (routers, firewalls) at their peak capacity means that they will be in a constant state of overperforming, which can affect the performance of the entire network
  • DDoS attacks and other types of cyber threats – sometimes, malevolent agents (ahem, hackers) might seize your network and use it to host various content on it, hogging the bandwidth and congesting the network. Other times, DDoS attacks might have a similar impact on your network.
  • Unfit Internet subscription – cheap Internet subscriptions are usually throttled or don’t offer you enough wiggle room. For instance, you might have a router/PC combo that can handle gigabit connections without a glitch, but your subscription is capped at 50 MBps.

Either way, you can see for yourself that there is more than just a few causes for network congestion. Therefore, you probably understand better now why there’s no magic fix for this issue.

More often than not, you can solve this problem easily by managing the network properly.

How to test for network congestion?

  1. Press the Win key on your keyboard
  2. Type CMD, right-click the Command Prompt and select Run as administrator
  3. In the CMD window type tracert google.comNetwork congestion test tracert
  4. Notice the number of hops it takes to reach the final server
  5. Take a look at the ping for each hop

In this case, when the final server is relatively far away, you might encounter issues on your side or on the receiving end. If the problem’s with you, you might want to try the fixes below.

If congestion occurs on the other end, waiting could be the most effective approach.

How to fix network congestion?

  • Monitor the traffic on your network and check for any bottlenecks or heavy usage patterns
  • Segment your network into multiple subnets that you can resize according to usage
  • Optimize the TCP/IP settings to balance the packet send/request speed
  • Use a CDN (Content Delivery Network) that will optimize resources by placing more requests on edge servers
  • Prioritize traffic on your network (for instance, VoIP services is always high-priority)
  • Use choke packets to reduce the output of sender devices, thus preventing network congestion
  • Opt for multi-hop routing, so that traffic can be routed over a different path whenever the default route starts queueing
  • Upgrade your Internet subscription to accommodate more devices and a larger bandwidth
  • Make sure your devices are up-to-date and not obsolete (even the cables)
  • Check for any attack attempts in your connection logs
  • Use a VPN such as Private Internet Access to bypass congestion (if the issue is on your ISP’s side)

Private Internet Access is an excellent VPN service from Kape Technologies that can help you bypass network congestion. However, you shouldn’t expect it to do wonders if the congestion is on your side, or on the receiving side of your connection (the destination server).

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If you ran the test as we described above and you’ve noticed abnormal traffic in the intermediary hops (those belonging to your ISP), you can try using a VPN to fix the situation.

Network congestion can be annoying, but it will likely pass

To wrap it up, even though network congestion can be a nuisance, it’s not the end of the world. Most likely it’s a passing issue, so patience is usually the best way to handle it.

However, if you know for a fact that your network quality is poor, you can try tweaking it (if you’re a network administrator). Alternatively, contact the network manager and bring the tweaks above into discussion.

FAQ: Learn more about network congestion

  • Does VPN solve network congestion?

If the issue is located somewhere on your ISP’s side, a VPN such as PIA can help curb network congestion. However, don’t expect it to work wonders on slow connections and low-bandwidth subscription plans.

  • How to fix network congestion?

If you’re a network administrator, you can make sure your network is properly configured and sized, and that all devices operating on it are not outdated, damaged, or obsolete.

  • How to measure network congestion?

You can use third-party software solutions such as PRTG Network Monitor to monitor traffic on your network. Alternatively, you can use Windows’ built-in ping and tracert tools to notice any abnormal behavior on your network.