Some general questions about QoS

  • ATTENTION! As of November 1, 2020, you are not able to reply to threads 6 months after the thread is opened if there are more than 500 posts in the thread.
    Threads will not be locked, so posts may still be edited by their authors.
    Just start a new thread on the topic to post if you get an error message when trying to reply to a thread.


Very Senior Member
Can anyone advise me how best to set up QoS please? In particular…

Is it better to select manual or automatic setting?

Given that the main bandwidth-sensitive functions in my household are streaming and intermittent gaming (mostly using an xBox), which pre-set should I choose?

Which of the three Queue Discipline methods would be likely to give the best results?

Is the FreshJR variation needed for best results or is it only applicable in specific circumstances?

Is there consistency across supported models or is there significant variation and if so, is that largely due to differences in the hardware or are there some underlying firmware issues for some models?

Finally, what is the best way to confirm whether or not QoS is working as it should?

Not sure if it’s relevant, but my current router is an RT-AX88U.


Part of the Furniture
The router model and the firmware version installed is always relevant.

As is the ISP speeds you are paying for/achieving.

Generally, for an RMerlin powered router, FreshJR QOS script setup as suggested (see his thread) and even if left at defaults provides a measurable boost to system responsiveness and performance.


Very Senior Member
Thanks for that. I've set it up as recommended, but I'm puzzles by this remark, "and make sure Undf Prio is NOT 1:17" I ran the debug test and got a reading of 1:16 for this parameter. Is that OK?


Senior Member
Thanks for that. I've set it up as recommended, but I'm puzzles by this remark, "and make sure Undf Prio is NOT 1:17" I ran the debug test and got a reading of 1:16 for this parameter. Is that OK?
Yes, but if you use his suggested order, you should get 1:13.
Web Surfing
Video and Audio Streaming
File Transfers


Regular Contributor
I'm two weeks in to using FreshJR and Adaptive QoS with 20Mbps downlink and 4Mbps uplink broadband. With two of us working from home, e.g.: video calls and remote desktop networking and WiFi calling etc. (twenty+ devices: laptops, tablets, cellphones, Apple TV, thermostat, home automation, IP cameras), this has been stress-tested and it's working well.

First for testing I did Merlin FW upgrade to 384.15 on an AC68U with factory default settings, then installed FreshJR script following the instructions on the link above in this thread (the only initial mistake I made was not enabling JFFS scripts). I used the recommended FreshJR settings including fq_codel.

FreshJR debug shows: adaptive QOS: Undf FlowID: 1:13

For Bandwidth Monitor priority, everything is set default except High for a Siemens Gigaset internet VoIP telephone.

For static IPs and application classes in FreshJR customize menu: I put Apple TV as Streaming; the Siemens Gigaset telephone as VoIP; a networked Mac Mini to File Downloads; everything else do whatever FreshJR/Adaptive QoS allocate.

All I changed for FreshJR recommended settings was take 10% off the minimum reserved bandwidth downlink from Games and put that to Web Surfing downlink. I've also seen some video call apps like FaceTime and BlueJeans get put to the VoIP application class, so I took 5% off the minimum reserved bandwidth uplink from Games and put that to VoIP uplink.

Some applications don't always map to what you might expect the application class: for instance a Hangout video meeting today was in the Others category (not in any of these: VoIP, Web surfing, Streaming). So I'm assuming I need to keep reasonable minimum bandwidth (e.g.: ~20%) for many of the application classes, I'm following the FreshJR recommended settings - except for Games has little/no traffic observed on our network so I have reduced Games bandwidth, whilst leaving Games with the higher Adaptive QoS priority as recommended in FreshJR post (I have not changed any of the Adaptive QoS priorities).

Finally I did a factory default settings and firmware upgrade of 384.16 onto an AC66U-B1, which is the primary router, and manually entered the same settings tested earlier on the AC68U. It's working fine. Running a speedtest on using a MacBook Safari browser, with router Adaptive QoS turned off I see Overall score of C with a BufferBloat score of F; with router Adaptive QoS turned on all scores are A (with ~20% slower data speed which so far seems acceptable).
Last edited:


Occasional Visitor
First I speedtest a few times with the same server to find the top speed.

I use traditional QoS + fq_codel.

Plug those top speed numbers into the Upload/Download clamps and enable QoS.

(Generally you'll have to increase these numbers by some amount since the overhead calculations aren't perfect)

Then I keep speedtesting and adjusting the numbers until the QoS-enabled speeds are only a few megabits away from the top speeds without QoS.

And that's basically it, if your connection is consistent you've accomplished the most important part of QoS which is to prevent packet loss. You can go to "User-defined QoS rules" to adjust priority for services. This generally isn't necessary, I usually only use it to deprioritize internet traffic that doesn't really matter.


Senior Member
Interesting. On two different routers, those settings have given me 1:13, but, as stated, as long as it's not 1:17, it should be working.


Occasional Visitor
FYI: (IIRC) traditional QoS is incompatible with hardware acceleration.
This is true, and you might not notice a difference if your internet is slow enough. I don't use adaptive QoS because I don't use any of the Trend Micro features.


Regular Contributor
my bandwidth on the wan side is 195/12 Mbit. my vpn speed is 130-150 / 12 Mbit, sometimes I have 170-195 Mbit here too. Most clients connect via vpn. My question in this case is how much the qos manual value should be set or compared to?

Similar threads

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!