On Mon, Feb 22, 2021 at 08:51:32PM -0500, Steven Shockley wrote:
> I have OpenBSD 6.8 running on a Dell R210-II acting as a firewall/router.
> To combat bufferbloat I tried implementing FQ-CoDel queueing. The WAN
> bandwidth is advertised as 940 Mbit/sec down and 840 Mbit/sec up.
>
> I've tried adding one or the other of these lines to my pf.conf:
>
> queue outq on $ext_if flows 1024 bandwidth 1024M max 1024M qlimit 1024
> default
> or
> queue outq on $ext_if flows 1024 qlimit 1024 default
>
> In both cases, upload speeds drop from ~800 Mbit/sec to < 100 Mbit/sec.
> Changing the 1024M to other values makes little or no difference. To be
> fair, bufferbloat does improve, but that's quite a hit. I'm measuring using
> the dslreports.com speed test via wired ethernet through a Cisco 3750x.
>
> One possible complexity is that the internal interface is tagged VLANs, but
> if it were an MTU issue I'd expect it to affect performance across the
> board.
>
> Any suggestions? I'm happy to post dmesg/pf.conf/diagrams if they'd help.
> Thanks.
I've noticed a similar effect on a slower link (VDSL with 50 down/ 10 up).
In this case the VDSL modem presents an Ethernet switch, so there is no
pppoe or vlan involved in the box that runs pf.
As soon as I enable this example given in pf.conf(5):
queue outq on em0 bandwidth 9M max 9M flows 1024 qlimit 1024 \
default
I see only about 2 or 3 Mbit/s max upload during tcpbench.
Which is indeed quite a hit compared to 10M.
Without the queue tcpbench goes up to 9 Mbit/s. It varies a lot between
5 and 9, which I thought might be a reason for my issue with queueing
enabled.
Currently, I am simply running this setup without any queueing.
