Hi all
I want to share something I finally tracked down to the source (or so I believe) yesterday evening.
Thanks to Kev for bringing this performance issue to my attention. Kev noticed it on his hAP AC3, I noticed/replicated the same on my hAP ac and started digging...
I run hAP ac with 350/35 line from ISP, there is no fancy configs on Mikrotik, really basic NAT setup, ethernets and wifi linked on LAN bridge. I tend to run LTS branch these days.
When I run on gigabit ethernet the speedtest.net flatlines immediately at 350-380 download as expected. Problems begin when I go onto wifi - I noticed it depends on which RouterOS is running on the device. I have tested it multiple times, over and over... taking several days to test each variant in different network conditions (time of day) and different speedtest.net servers (also tested against fast.com which is Netflix AFAIR).
Anyway, here are common things that are fairly constant across all the tests:
- radio interface is set up as AP Bridge, 5GHz-only-AC, channel auto, width 20/40/80MHz XXXX, UK, regulatory domain
- my Mac shows that radio link speed is floating between 1170Mbps and 1300Mbps
Here is where things get strange - depending on version of RouterOS (all below are LTS):
- RouterOS 6.44.6 - wired speed 350+, wireless speed 350+ Mbps
- RouterOS 6.45.9 - wired speed 350+, wireless speed 350+ Mbps
- RouterOS 6.46.8 - wired speed 350+, wireless speed 50-80 bursting to 90-100 Mbps for short durations of time
- RouterOS 6.47.9 - wired speed 350+, wireless speed 35-50 bursting to 70-80 Mbps for short durations of time
I was upgrading and downgrading ROS versions and monitoring what changes in behaviour, without touching config on the device and finally settled on 6.45.9 as the last LTS release working at full speed.
Another observation:
I run DNS cache/resolver/forwarder on Mikrotik, handing off queries to Pi-Hole running on home server, so mikrotik asks pi-hole, all machines ask mikrotik... Since update to 6.46.8 I started getting odd DNS timeouts and my network monitoring scripts light up the dashboard like a Christmas tree several times a day, with ROS 6.46.8 or above it happens every 10-15min, sometimes on and off for hours... but again, since going back to ROS 6.45.9 problem disappeared completely.
Now, I have no clue what may be the reason for this, I hope some really smart people here will be able to work this out. For now I run 6.45.9 LTS and I'm happy with the outcome, but my OCD kicks in and I need to understand what caused it. May it be a bug in ROS, maybe some driver change, maybe something else? Fingers crossed someone will know the answer.
Cheer
Tom