just curious, i'm familiar with htb and its rate-limiting properties, but netem apparently delays/reorders packets for a specified amount of latency time, not bandwidth speed. why would this be useful?

What if you had to test an application in an area of high latency? e.g. a remote area like in Africa or a low bandwidth/high latency network (e.g. mobile). You'd want to simulate network conditions in an environment as close to what it would run in as possible. What if your application was to run on a lander on Mars? The latency would be extremely high there so that's where you would see such delays. I only gave you a few simple examples but there's many examples why one would want to emulate poor network conditions to test the reliability of an application.

got it, so it's just for testing, i was thinking it might have some other more active reason for use. thanks