[Cerowrt-devel] Ubiquiti QOS

Mikael Abrahamsson swmike at swm.pp.se
Sun May 25 20:18:30 EDT 2014

On Sun, 25 May 2014, dpreed at reed.com wrote:

> The optimum buffer state for throughput is 1-2 packets worth - in other 
> words, if we have an MTU of 1500, 1500 - 3000 bytes. Only the bottleneck

No, the optimal state for througbut is to have huge buffers and have them 
filled. The optimal state for interactivity is to have very small buffers. 
FQ_CODEL tries to strike a balance between the two at 10ms of buffer. PIE 
does the same around 20ms. In order for PIE to work properly I'd say you 
need 50ms of buffering as a minimum, otherwise you're going to get 100% 
tail drop and multiple sequential drops occasionally (which might be 
desireable to keep interactivity good).

My comment about 50ms is that you seldom need a lot more.

Mikael Abrahamsson    email: swmike at swm.pp.se

More information about the Cerowrt-devel mailing list