[Bloat] AQM and PPP on Linux

[Jonathan Morton]

> On 28 Jul, 2015, at 17:31, Simon Barber <simon at superduper.net> wrote:
> 
> The issue is that Codel tries to keep the delay low, and will start dropping when sojourn time grows above 5ms for 100ms. For longer RTT links more delay is necessary to avoid underutilizing the link.

I’m pretty sure we’ve had this discussion before, several times.

Codel works pretty well, with an interval of 100ms, when the actual RTT is between about 10ms and 1000ms.  That accounts for 99.9% of the practical paths you’ll see on the Internet.

If you really are concerned about long-RTT paths, then you can increase the interval parameter to suit.  This will hurt Codel’s performance slightly on very short-RTT paths.

 - Jonathan Morton