[Tutorial] - How to configure fq_codel for comcast to help bufferbloat / QoS

[meyergru]

The ECN standard is pretty new in networking periods of time, so not everybody (i.e. ISP) supports it properly.

Using it can have adverse effects because some router equipment may abort the connection if it sees the previously reserved bits that are now being used for ECN. That is why I disabled it after seeing problems with traffic shaping with ECN enabled, alas to no avail.

So, there is no real suggestion. Theoretically, ECN would allow to signal that a congestion is imminent, so that is a plus. But if it is implemented poorly or not at all on your ISP's side, it is counter-productive.

[Seimus]

Basically I agree what @meyergru said.

There are no clear instructions on this, you can enable it and if you don't see any problems on the flows (sessions/connections) keep it enabled.

What does slow start refer to exactly and is there an easy way to test it?

Slow start is exactly what is says "slow start of the flow" "TCP slow start", meaning you download something but it takes a while to reach the throughput it should.

In regards of tests, there are several tools than can be used to test it scientifically. For example crusader. But as well speed test can show it, those one mentioned in the Docs guide, or Iperf3. Or you can see it on real live flows if you see the throughput values.

Regards,
S.

[neo243]

@theogravity Thanks for creating this works nicely!