Okay, this is a sub-optimal configuration, you should use layer_cake.qos instead, simple.qos/cake is possible for reference testing, but does not make much sense in production, as you will run both cake and HTB...
https://lede-project.org/docs/user-guide/sqm has a bit more detail on sqm-scripts configuration
Could you post the output of:
- cat /etc/config/sqm
- tc -d qdisc
- tc -s qdisc
followed by a dslreports speedtest (have a look at https://forum.openwrt.org/t/sqm-qos-recommended-settings-for-the-dslreports-speedtest-bufferbloat-testing/2803 for how to get the most out of that speedtest). BTW, this is not because I dislike speedtest.net, it is just that the detailed results page from dslreports offers way more information that is helpful when trying to test/optimize sqm-scripts.
Followed again by
5) tc -s qdisc
And finally run dslreports speedtest while concurrently log into your router and run "top -d 1" and look at the idle and sirq values; if idle is always 0 or close to 0, your router simply runs out of CPU cycles (traffic shaping is unfortunately a bit expensive).
Yes, for ingress shaping a bit of bandwidth sacrifice is necessary, but most users are happy with something in the range of 85-95% of the gross download bandwidth.
without any QoS you only get
(8.281000^2)/(10001000) = 65.6 Mbps (which matches the speedtest.net number of 65 quite well).
if we try to calculate the respective gross rate (brutto-bandbreite) we get:
(8.281000^2) * ((1500+26)/(1500-8-20-20)) / (10001000) = 68.94 Mbps
So, I guess the 6431 is a lot less capable than the FB 7360v1...
I ran into a similar issue with a BT hoe hub 5a, that box was not powerful enough (under lede at least) to do VDSL2, PPPoE, NAT, firewalling and wifi even at a 50/10 VDLS2 link. So I turned that box into a dedicated bridged modem, and have an old wndr3700v2 do PPPoE, NAT, firewalling and wifi, which for whatever reason has no issues doing all of that. And I also would really like to reduce my router park a bit...
Best Regards
True, this is why sqm-scripts defaults to ECN on the downstream, so that packets do not need to be dropped 9assuming both endpoints negotiated ECN).