[Cake] Trouble getting decent performance with CAKE

[Dave Taht]

As much as I like to get the fustest with the mostest with the rrul
test, it is often easier to test up and down separately.

do :

tc qdisc delete ifb0 root
tc qdisc delete eth0 root

I am not sure what imq is being used for....

Can you share the output of tc -s

instead?

a simple upload test would then be:

(unless you made cake the default)

flent -t pfifo_fast -H wherever --socket-stats -x --te=upload_streams=4 tcp_nup

tc qdisc add dev eth0 root cake all_your_options

flent -t cake -H wherever --socket-stats -x --te=upload_streams=4 tcp_nup

the download setting up tc mirred I assume you are doing with sqm? Do that.

flent -t -H wherever --socket-stats -x --te=download_streams=4 tcp_ndown

then send tc -s

It's entirely feasible your so-called 100mbit service is running at
far far less than 100mbit in the first place.

Another thing to check is if your modem is connecting to the device at
100Mbit or a gbit. SOME - not enough - dsl modems actually connect at
100Mbit and/or joy of joys excert hw flow control.
95Mbit is gonna be slightly too high in former case for cake to
control things, try 92mbit, or less.

On Tue, Jan 26, 2021 at 4:22 PM <jmarks2 at gmail.com> wrote:
>
> Dear CAKE experts,
>
> I write for your help in getting CAKE to perform on my router as I understand it should.
>
>
>
> I replaced my aging Asus home router with a Ubiquiti Edgerouter 4 specifically so I could take advantage of the port of CAKE to it.
>
>
>
> I am in the US, with VDSL2 service provided by AT&T at 100/20. I now have all unfiltered traffic delivered by the AT&T modem to the eth0 port on the router.
>
>
>
> My desktop runs Windows. So, to take advantage of flent to quantify CAKE performance, I stood up a Linux Mint VM and ran flent rrul tests before CAKE installation, and after.
>
>
>
> The first attached datafile, labeled qdisc pfifo fast, is the performance before CAKE. The other file, called 20/95 ack filtered bridged ptm, is my latest attempt with configuring CAKE flags.
>
> My major issue is with Ingress. Egress seems fine.
>
> For ingress, I see very little difference between performances with and without CAKE. And the overall throughput is far less than 100 mbit.
>
>
>
> The queuing disciplines on the router are:
>
>
>
> jeremymarks at ubnt:~$ sudo tc qdisc show
>
>
>
> qdisc cake 1: dev eth0 root refcnt 2 bandwidth 20Mbit besteffort dual-srchost nat nowash ack-filter split-gso rtt 100.0ms ptm overhead 22 no-sce
>
> qdisc ingress ffff: dev eth0 parent ffff:fff1 ----------------
>
> qdisc pfifo_fast 0: dev imq0 root refcnt 2 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
>
> qdisc cake 2: dev ifb0 root refcnt 2 bandwidth 95Mbit besteffort dual-dsthost nat nowash ingress ack-filter split-gso rtt 100.0ms ptm overhead 22 no-sce
>
>
>
> I must be making a major mistake in configuring CAKE.
>
>
>
> I would be grateful for any help or advice in getting this amazing program to work as it should.
>
>
>
> Many thanks for any help.
>
> Jeremy
>
>
>
>
>
> _______________________________________________
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> Cake at lists.bufferbloat.net
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-- 
"For a successful technology, reality must take precedence over public
relations, for Mother Nature cannot be fooled" - Richard Feynman

dave at taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729