[Bloat] Up-to-date buffer sizes?

Jesper Dangaard Brouer jbrouer at redhat.com
Wed Mar 9 12:24:57 EST 2022



On 09/03/2022 17.31, Toke Høiland-Jørgensen via Bloat wrote:
> Michael Menth <menth at uni-tuebingen.de> writes:
> 
>> Hi all,
>>
>> are there up-to-date references giving evidence about typical buffer
>> sizes for various link speeds and technologies?
> 
> Heh. There was a whole workshop on it a couple of years ago; not sure if
> it concluded anything: http://buffer-workshop.stanford.edu/program/
> 
> But really, asking about buffer sizing is missing the point; if you have
> static buffers with no other management (like AQM and FQ) you're most
> likely already doing it wrong... :)

Exactly, I agree with Toke. The important parameter is the latency.
Or the packet sojourn time (rfc8289 + rfc8290) observed waiting in the 
queue.

The question you should be asking is:
  - What is the max queue latency I'm "willing" to experience on this link?

Hint, you can then depending on the link rate calculate the max buffer 
size you should configure.

The short solution is:
  - just use fq_codel (rfc8290) as the default qdisc.

--Jesper





More information about the Bloat mailing list