On 2018-08-08, Mik J <mikyde...@yahoo.fr> wrote: > Hello Daren, > Thank you for your answer, I didn't see it earlier today. > This change in current makes sense to me. > Regards > > > Le mercredi 8 août 2018 à 06:07:10 UTC+2, Darren Tucker > <dtuc...@dtucker.net> a écrit : > > On 8 August 2018 at 05:29, Mik J <mikyde...@yahoo.fr> wrote: >> Does anyone knows what means lowdelay and thoughput for IPQoS parameter ? >> To what DSCP correspond these words > > From https://www.openssh.com/specs.html, which documents the most > recent release: they're the values specified in RFC1349, the first of > the dozen or so attempts to specify the meaning of those few bits > (RFCs 2474, 2597, 2598, 3168, 3246, 3260, 3662, 4301, 4594, 5865 and > 8325). > >> I did a capture when writing ls in my terminal and I see DSCP=cs0. >> I would have expected something else. > > The default values have been changed in -current but that change has > not yet made it to a release. From > https://man.openbsd.org/ssh_config.5: "The default is af21 > (Low-Latency Data) for interactive sessions and cs1 (Lower Effort) for > non-interactive sessions." >
The old implementation using TOS pre-dates common use of DSCP and held on for quite some time, I think there may have been earlier concerns about network equipment not passing DSCP-marked packets properly. People using PF queues might like to note that "set queue" used with 2 queue names (e.g. "set queue (bulk, interactive)") only prioritises TOS=lowdelay, not DSCP. So people using this for prioritisation of interactive SSH traffic might want to consider either replacing the queues with "flow queues" (interactive packets are usually smaller and likely to below the "quantum" size and so have priority), or using "IPQoS lowdelay throughput" in ssh config.
