Your speed test looks fine, but bufferbloat is why your Zoom calls still lag

Published Sep 25, 2026, 2:30 PM EDT João has been covering the tech world for over 7 years, with a heavy focus on laptops and the Windows ecosystem. I also love all things tech and videogames, especially Nintendo, which he's always happy to talk about. Prior to joining XDA in 2021, he worked at Neowin: https://www.neowin.net/news/poster/jo%C3%A3o-carrasqueira/ When it comes to your home network, it's always upsetting when you pay for a plan with fast upload (and download) speeds only to end up struggling during certain online activities. In many cases, video calls or online gaming can be very unreliable, even when speed tests seem to show everything is okay. What you might not realize is that your upload speeds aren't really the problem. The problems with video calls or other activities that require low latency may have to do with something called bufferbloat, and thankfully, there is a solution. Unfortunately, it may not be a free one. Bufferbloat can slow down your entire network It's all in your router Bufferbloat is a phenomenon that can occur when your network is populated by a lot of devices, and it's likely to get worse as your network grows. When your devices try to send data to the internet, those data packets get queued up in the router to be sent, and when more devices come online, those requests can pile up. This accumulation of requests can lead to latency in activities that require fast responses, like video calls, online multiplayer, cloud streaming, and others. The router can't immediately process new requests when existing ones are still being handled, so anything new that you try to do can cause a slowdown for other devices and tasks. That's what we call bufferbloat, and it can be a big problem. It's important to rule out bufferbloat as a potential cause of latency issues, and thankfully, some speed tests can help you do that. I used this one by a company called Waveform and, following the general recommended procedures, and it showed me my network has a reasonable amount of bufferbloat, though far from the worst it could be. I do have a pretty good router to begin with, which is why these results are generally pretty positive and I have no major issues with my internet. I recommend running this test first to see if you spot an abnormal spike in latency when other activities are using your network. The ideal way to test this is to run the test over a wired connection and with no major internet activity going on, meaning no big uploads or downloads, no streaming, and no backups. That helps the test determine the impact of a single source of requests. SQM is the solution Managing your queue fixes this If bufferbloat is causing extra latency on your network, the best way to fix this is with a feature called SQM, or smart queue management. This feature is available on certain router models depending on the firmware they use, or you may be able to get it by installing OpenWrt on a compatible router model, since the feature is also available there. Once enabled, SQM allows a router to prioritize and manage requests from connected devices and prevent them from piling up, leading to lower latency, especially during peak usage hours. This is a CPU-intensive workload, so older or lower-end routers may not be able to support it, but a lot of higher-end models do have it. I happen to have a GL.iNet Flint 2 router at home (and I've talked about how much I like it before), which does support this feature, though it's disabled by default. On this firmware, you can find SQM under the Flow Control section, though this will depend on your router model. After enabling SQM, the latency on my network didn't really change, but again, I had pretty good results to begin with. If you saw big spikes in your initial test, this could make a big difference for you. Many routers don't have it You may need an upgrade The problem with SQM is that it's a solution not present on a lot of routers that may end up in your home. The Flint 2 is a more enthusiast-oriented router, so it does have this capability, and so do a few other brands, including some eero models, custom software like pfSense, OPNSense, and OpenWrt on supported and other higher-end products. If your test results are already positive, there may be no reason to invest in a whole new router, especially considering they can get fairly expensive. If you are in the market for one, I do love my GL.iNet Flint 2, but there are also updated models already available that also support the feature. There are some potential downsides It's not a one-size-fits-all solution If SQM can fix the bufferbloat problem, why isn't it just on every router, or at least enabled by default on the models that have it? Well, like many things in tech, it's not a miracle cure. For one thing, SQM can come at the cost of peak throughput on your network, meaning measured speeds can actually be lower. That's actually one of the warnings shown on my router when I access the SQM page, and a potentially good reason for it to be disabled. What's more, as I've already mentioned, SQM is CPU-intensive, so your router needs to work much harder and thus, use more power, which could mean a higher electricity bill at the end of the month. I also noticed that on my router model, SQM conflicted with a feature called Network acceleration, which I had enabled. So, in some cases, there may be more benefits to a different router feature compared to SQM. And the benefits of SQM depend heavily on the scenario. Bufferbloat can be a common problem, but it's potentially not as common as the many other factors that can affect your network, such as channel congestion, so the extra power consumption and potential hit to maximum speeds isn't always going to be worth it. Running that test first is essential before deciding to invest in a new router or even just changing a setting. Your ISP isn't always the problem If you've been struggling with internet performance, even when all the tests say everything is okay, consider testing your router's bufferbloat. It can have a bigger impact than you think, and even small requests can pile up can interfere with your network's reliability. It's not a wide-ranging panacea, but it's another important factor to be aware of. Of course, there are other things you can play around with, like your router's airtime or the channel width.