A BDP is not a large buffer. I'm not unveiling a secret.

And it is just a rule of thumb to have an idea at which working point the protocol is working.

In practice the protocol is usually working below or above that value.

This is where AQM and ECN help also. So most of the time the protocol is working at way

below 100% efficiency.

My point was that FQ_codel helps to get very close to the optimum w/o adding useless queueing and latency.

With a single queue that's almost impossible. No, sorry. Just impossible.

On Tue, Nov 27, 2018 at 11:50 AM Mikael Abrahamsson <swmike@swm.pp.se> wrote:

On Tue, 27 Nov 2018, Luca Muscariello wrote:

> link fully utilized is defined as Q>0 unless you don't include the
> packet currently being transmitted. I do, so the TXtteer is never idle.
> But that's a detail.

As someone who works with moving packets, it's perplexing to me to
interact with transport peeps who seem enormously focused on "goodput". My
personal opinion is that most people would be better off with 80% of their
available bandwidth being in use without any noticable buffer induced
delay, as opposed to the transport protocol doing its damndest to fill up
the link to 100% and sometimes failing and inducing delay instead.

Could someone perhaps comment on the thinking in the transport protocol
design "crowd" when it comes to this?

--
Mikael Abrahamsson email: swmike@swm.pp.se