Simple Queues CIR not working as expected

RouterOS Beginner Basics
1

Hello MikroTik community,

I am trying to set up a configuration of simple queues that guarantees a certain bandwith for
my “main” computer at any given time. I’ve already researched a lot about this and tried various
things including mangling and marking my traffic, setting up a queue tree but nothing
seems to work for me. The “limit-at” option just seems to have no effect.

At the end, I would like to stick to simple queues because I believe I do not need to mark
my traffic for this. Currently I am using this configuration:

/queue simple
add dst=pppoe-out1 max-limit=15M/80M name=wan packet-marks=no-mark queue=\
    ethernet-default/ethernet-default target=192.168.0.0/24
add comment="Main PC" limit-at=10M/50M max-limit=15M/80M name=prioq \
    packet-marks=no-mark parent=wan queue=ethernet-default/ethernet-default \
    target=192.168.0.180/32
add comment="Other devices" limit-at=4M/25M max-limit=15M/80M name=rest \
    packet-marks=no-mark parent=wan queue=ethernet-default/ethernet-default \
    target=192.168.0.0/24

To test if the CIR is acutally working I am starting a download of a large file on
another computer in the network lets call it “PC2”. When I then execute a speedtest on my main PC,
the download rate of “PC2” drops way below the expected 25M (to around 7M and
stays there as long as the speed test is executed).

In this case I would have expected that the download rate of PC2 will drop to 25M.

I do not have fasttrack enabled in my firewall rules.

Do you have any idea what could be the issue here?

2

I forgot to add some details to this:

The device I am using is a HAP AC2. The queues seem to work in general. The traffic statistics
in all queues show correct values. Setting a “Max Limit” also works correctly. When I set the
“Max Limit” to 40M for my Main PC,speedtest shows around 39M download. Same is true for
the “other” queue.

However, I do not want to waste any bandwith when it is not required by the “other” devices by
setting hard “Max Limit” parameters. So I tried to work with “Limit at” but unfortunately, this seems
to have no effect.

3

Hi Everybody,

meanwhile I found the solution for the problem!

The speed “Max-Limit” settings were set too high so that actually my modem throttled
the traffic which messed up the queueing!

I have now set the “Max-Limit” to 95% of my speed in all queues. With this setting it
works perfectly! I hope this will also be useful for someone else, find the working settings
below:

add dst=pppoe-out1 max-limit=14M/76M name=wan packet-marks=no-mark queue=\
    ethernet-default/ethernet-default target=bridge1
add comment="Main PC Prio" limit-at=10M/50M max-limit=14M/76M name=prioq \
    packet-marks=no-mark parent=wan priority=7/7 queue=\
    ethernet-default/ethernet-default target=192.168.0.180/32
add comment="Other devices" limit-at=4M/26M max-limit=14M/76M name=rest \

Additionally, I have seen that starting a speedtest at “speedtest.net” while “PC2”
downloads was not the best way to test my queues. I did another test where I started
a download of a big 10G dummy file on both machines simultaniously and check the
traffic rates directly in the queue monitor.

However, when I execute a speedtest it still seems to “ignore” the limit-at setting
or bypass the queues. I wonder why this is the case…