On Wed, Aug 7, 2019 at 7:55 PM Josh Hunt <joh...@akamai.com> wrote: > > The current implementation of TCP MTU probing can considerably > underestimate the MTU on lossy connections allowing the MSS to get down to > 48. We have found that in almost all of these cases on our networks these > paths can handle much larger MTUs meaning the connections are being > artificially limited. Even though TCP MTU probing can raise the MSS back up > we have seen this not to be the case causing connections to be "stuck" with > an MSS of 48 when heavy loss is present. > > Prior to pushing out this change we could not keep TCP MTU probing enabled > b/c of the above reasons. Now with a reasonble floor set we've had it > enabled for the past 6 months. > > The new sysctl will still default to TCP_MIN_SND_MSS (48), but gives > administrators the ability to control the floor of MSS probing. > > Signed-off-by: Josh Hunt <joh...@akamai.com> > ---
Acked-by: Neal Cardwell <ncardw...@google.com> Thanks, Josh. I agree with Eric that it would be great if you are able to share the value that you have found to work well. neal
