On Wed, 9 Mar 2016 12:58:39 -0500
Christopher Sean Hilton <ch...@vindaloo.com> wrote:
> I've also been trying to get help with queuing. Perhaps we can help
> each other out.
>
> I'm using queuing to alleviate bufferbloat and make my son's gaming
> performance better. I'm on an asymetric cablemodem connection here in
> the U.S. My download is 100M and my upload is 40M. I use a queue
> definition similar to this:
>
> queue ext_iface on $ext_if bandwidth 1000M max 1000M qlimit 512
> queue download parent ext_iface bandwidth 120M max 120M
> qlimit 128 default
> queue ext_extra parent ext_iface bandwidth 880M max 880M
> qlimit 384
>
> queue int_iface on $int_if bandwidth 1000M max 1000M qlimit 512
> queue upload parent int_iface bandwidth 40M max 40M
> qlimit 48 queue int_internal parent int_iface bandwidth 960M max 960M
> qlimit 464
>
> I found several things. Firstly, I found that all queues seem to have
> an implied parent queue that based on their interface with a
> bandwidth of their
> interface speed. Thus:
>
> queue download on $ext_if bandwith 120M default
>
> really meant:
>
> queue download on $ext_if bandwidth 120M max 1000M default
>
> hence my specification of the interface queue.
>
> I'm trying to limit the bufferbloat so the depth of the queue is very
> important. I chose values for qlimit that keep the amount of time that
> a packet would traverse a queue down at the 0.015ms range:
>
> 40Mbit/s / ( 8 bit/byte * 1500 byte/packet) * 0.015s = 50 packets
>
> I used 48 because I'm keen on multiples of 16.
>
> Have you tried anything like this?
Taking into account the fact that I can't make this work, I guess I am
not the person whose advices should be followed :)
Nevertheless, I found out that you really need to set both bandwidth and
max bandwidth to 95% or less of what you really get from your provider
(I get almost 20% less than advertised), otherwise no shaping takes
place at all. Rough measurement can be done even with bandwidth testing
sites, where you gradually lower your parent queue bandwidth until you
notice you get less bandwidth than what you would get without shaping.
Difference between units such as M, Mbit, Mb, MB will complicate things
further.
If you don't mind setting fixed-bandwidth queues, I suggest you set
them as follows:
-----
gamer = "{ IP.ADD.RE.SS }"
queue upload on $ext_if bandwidth 40M min 40M max 40M
queue gamer parent upload bandwidth 10M min 10M max 10M
queue other parent upload bandwidth 30M min 30M max 30M default
queue download on $int_if bandwidth 400M min 400M max 400M
queue gamer parent download bandwidth 100M min 100M max 100M
queue other parent download bandwidth 300M min 300M max 300M default
match from $gamer to any set queue gamer
match from any to $gamer set queue gamer
-----
Actually this configuration, with only two queues, is the only one I
found to work even with non-fixed-bandwidth queues - if you don't
specify min and max on child queues, one queue will get all the parent
queue bandwidth until the other one kicks in. If both queues demand
maximum bandwidth, they will be shaped to their set bandwidth.
Unfortunately, this stops working on introduction of 3rd queue.
After changing anything in ruleset, do not forget to flush your states
with 'pfctl -F states', and check in 'systat states' there are no rules
marked with '*'.
I never got to tuning qlimits, as I never found anything in pf.conf
manpage about it, and I follow the rule of a thumb 'do not push buttons
if you don't know what they do'. I thought default of 50 is good
general-purpose value.
Hope this helps.
--
Before enlightenment - chop wood, draw water.
After enlightenment - chop wood, draw water.
Marko Cupać
https://www.mimar.rs/
