It's a problem in various networking devices, in which those devices buffer too heavily rather than dropping packets. That behavior may be implemented in a comb

It's a problem in various networking devices, in which those devices buffer too heavily rather than dropping packets. That behavior may be implemented in a combination of hardware/firmware/software. Among other things, this prevents other devices from being able to adapt to bandwidth limits (because dropped packets are the primary way to signal "slow down"), and causes high latency (because packets are sitting in deep buffers for a while). Software such as network schedulers in Linux can work around that problem. But ultimately, it should be fixed in the various networking devices that create the problem in the first place.