It is true that there is an interplay between bandwidth utilization and latency. However (assuming no prioritisation), if your bandwidth is at least double you

It is true that there is an interplay between bandwidth utilization and latency. However (assuming no prioritisation), if your bandwidth is at least double your video conference bandwidth requirements then a download shouldn’t significantly affect the video conference since TCP tends to be fair between streams. Even when I was on a 10Mb/s line I found gaming and voice was generally fine even with a download. However, if you’re using peer to peer (like BitTorrent), then that is utilizing dozens or hundreds of individual TCP streams and then your video conference bandwidth getting equal amount per all other streams is too slow. Bufferbloat exacerbates high utilisation symptoms because it confounds the TCP algorithms which struggle to find the correct equalibrium due to “erratic” feedback on if you’re transmitting too much. It’s like queuing in person at a government office and not being able to see past a door or corner how bad the queue really is, if you could see it’s bad you might come back later, but because you can’t you stand a while on the queue only to realize quite a bit later you’ll have to wait much longer than you initially expected, but if you’d known upfront it would be bad you might have opted to come back later when it’s more quiet. Most people feel that since they’ve sunk the time already they may as well wait as long as it takes, further keeping the queue long. Higher throughput would help, but just knowing ahead that now’s a bad time would help a lot too. I do wish most consumer ISPs supported deprioritising packets of my choice, which would allow you to download things heavily at low priority and your video call would be fine.