Re: buffer bloat and packet pacing

[Brett Frankenberger <rbf+nanog () panix com>]

On Thu, Sep 03, 2015 at 05:48:00PM +0300, Saku Ytti wrote:
> Hey Brett,
>
> > Here's a paper that shows you don't need buffers equal to
> > bandwidth*delay to get near capacity:
> > http://www.cs.bu.edu/~matta/Papers/hstcp-globecom04.pdf
> > (I'm not endorsing it.  Just pointing out it out as a datapoint.)
>
> Quick glance makes me believe the S and D nodes are equal bandwidth,
> but only R1-R2 bandwidth is explicitly stated.S1, D1, Sn, Dn are only
> ever mentioned in the topology. If Sender is same or lower rate than
> Destination, then we really shouldn't need almost any buffering.

Unless Sender is higher than R1-R2.

> Issue should only come when Sender is significantly higher rate than
> Destination and network is not limiting them.

I didn't read it in detail either, but at first glance, it appears to
me that the model is infinite bandwidth and zero latency between S and
R1, and D and R2, with queueing happening in R1.

That's not going to give materially different results than, having S-R1
be 4 times R1-R2, and R2-D being the same as R1-R2.  So it fits well
with the original discussion here of 40G into 10G.

     -- Brett