Using traffic shaping, is limiting download traffic helpful or harmful?

Solution 1:

The main reason you may want to use incoming traffic shaping is to prevent the bufferbloat problem. If your Internet connection is ADSL or Cable Internet, and the upstream device has large buffers (it usually does), what happens is that latency goes through the roof once your link is fully saturated. Therefore you cannot use latency-critical services like VoIP at the same time as you're downloading stuff, etc.

In this scenario, shaping incoming traffic to about 90% of your maximum available incoming bandwidth lets you keep the latency at manageable level, without affecting your overall throughput much.