AC86U: Comments setting up Traditional QoS

[jeden]

I have had very erratic results setting up Traditional QoS and I would like to ask for comments.

- The default priority seems to be "Low". That is unexpected, I had assumed it would be "Medium". This is not described anywhere in the web interface and knowing that would've saved me a lot of time. There's a "QoS FAQ" link in the "QoS - QoS to configuration" section but it is broken.

- I don't understand why there's an option to set a % limit of bandwidth for each category and it is configured by default to be lower than 100% for some categories. Aren't priorities enough?

- Even after setting a certain category to, say, 90% of my download bandwidth (and by looking at the MB/s counter, it is certainly lowered) my ICMP traffic (such as pings) is still terribly delayed. The only way to assure it's not delayed is by lowering the maximum bandwidth of whatever category by a lot, which means I lose a lot of bandwidth; I don't have a lot of bandwidth to begin with so this is not optimal.

- I haven't found a way to know to which category a certain connection is set. I had a router before that would show me a list of all connections along with what QoS category they had; this router seems not to have anything like it in the web interface (perhaps there's something in SSH, I'd like to know). Additionally, the "Classification" section seems to be broken since it displays what seems an empty interface:

- The only way to make the "Bandwith Monitor" section reliable (or work at all) is by enabling the "Apps analysis" option, which forces me to accept a EULA from a 3rd party; I find this to be unacceptable. There is a "WAN/LAN Bandwidth Monitor FAQ" link in the "QoS - WAN/LAN Bandwidth Monitor" section but once again it is broken.

- You can add QoS rules based on the source of traffic, but not the destination (?????). Additionally, all QoS rules you add are applied to both download and upload—you can't add rules that only apply to either.

I would appreciate any input because the QoS feature is very important for me. I am thinking of reverting to stock and see if it works there but I want some guidance of the experts before I do that.

 

[Klueless]

- I don't understand why there's an option to set a % limit of bandwidth for each category and it is configured by default to be lower than 100% for some categories. Aren't priorities enough?

My guess?

High priority does it's thing until its queue is empty then the next priority down gets to unload. If "High" was set to 100% it is "possible" the next one down would never get a turn.

So setting each for something less than 100% gives the next guy down some chance.

 

[jeden]

But that's what "Minimum Reserved Bandwidth" should be for... but, for some reason, it's only available for upload, and not for download. Which is yet another thing I do not understand.

 

[dave14305]

But that's what "Minimum Reserved Bandwidth" should be for... but, for some reason, it's only available for upload, and not for download. Which is yet another thing I do not understand.

I think of it as minimum guaranteed bandwidth per priority so that no priority gets starved. You might want VoIP to be high priority with at least 5 Mbps...

 

[jeden]

I tried to go back to stock and, while the performance of the QoS feature on Merlin is not that good, on the stock firmware QoS simply does not work at all! What a disappointing router for its price...

 

[dave14305]

I tried to go back to stock and, while the performance of the QoS feature on Merlin is not that good, on the stock firmware QoS simply does not work at all! What a disappointing router for its price...

Adaptive QoS performance is very good on Merlin. If you're stuck on Traditional QoS for some reason (e.g. Trend Micro tinfoil hat), then yes, performance without NAT acceleration will be worse. Merlin + Adaptive QoS + FreshJR_QOS script is very good.

 

[jeden]

I want to use Traditional QoS because I am competent enough to write my own QoS rules and I want to be able to fine-tune them.

I have an ADSL connection, so the problem here is not that I'm reaching the limits of the router's CPU, I can assure you.

 

[L&LD]

The problem is that Asus' (and therefore RMerlin's too) Traditional QoS has been broken for 'forever'.

I suggest using what works.

 

[dave14305]

See https://www.snbforums.com/threads/rt-ac88u-traditional-qos-fully-fixed-i-believe.45113/

There was a commit by this guy back in 2018.
https://github.com/RMerl/asuswrt-me...cd611d9#diff-0ce185eab5df0c4ccc5b7b38744507f1

 

[ironclad]

I agree with you that this feature kinda sucks but it does work on my end. This is just a low-end RT-AC68u on Merlin 384.16. Make sure you're on the latest firmware, older ones have a bug where the upload/download clamps are reversed.

- The default priority seems to be "Low". That is unexpected, I had assumed it would be "Medium". This is not described anywhere in the web interface and knowing that would've saved me a lot of time. There's a "QoS FAQ" link in the "QoS - QoS to configuration" section but it is broken.

It leads here: https://www.asus.com/support/FAQ/1010951
It's just semantics. It actually doesn't matter if the default priority is low because that priority can still use 100% bandwidth when nothing is contesting it.
"If there are no packets being sent from high-priority applications, the full transmission rate of the Internet connection is available for low-priority packets."

- Even after setting a certain category to, say, 90% of my download bandwidth (and by looking at the MB/s counter, it is certainly lowered) my ICMP traffic (such as pings) is still terribly delayed. The only way to assure it's not delayed is by lowering the maximum bandwidth of whatever category by a lot, which means I lose a lot of bandwidth; I don't have a lot of bandwidth to begin with so this is not optimal.

I think this is user error. ICMP packets are already prioritized (so the "The Highest Priority packet" table claims). If your packets are getting a huge delay it's probably because your Upload/Download values in QoS_EZQoS.asp are misconfigured and too high (mostly upload). You should set them so your speedtest results are slightly lower than what your connection can offer.

(bear in mind that QoS doesn't work that well with extremely slow internet to begin with)

I don't understand why there's an option to set a % limit of bandwidth for each category and it is configured by default to be lower than 100% for some categories. Aren't priorities enough?

You might not want a set box that plays media to waste all your upstream bandwidth for example if it's only supposed to download. Just one example I could think of.

Additionally, the "Classification" section seems to be broken since it displays what seems an empty interface:

This one's a mystery to me. Most of the time it displays the pie chart but the table UNDER the pie chart only shows up if I open the Bandwidth Monitor in a new tab.

Here I classify all UDP traffic to outbound port 1194 as "high" priority and it seems to work. Note that if you're adding new rules you have to break the connection and connect again before the rules will apply.

- The only way to make the "Bandwith Monitor" section reliable (or work at all) is by enabling the "Apps analysis" option,

This feature is FUBAR for me too. Sometimes it doesn't update and sometimes it attaches the wrong device to the wrong bars. Sometimes hitting the apply button fixes it. Sometimes opening up all the QoS pages in different tabs makes it work. Why does it do this? Who knows.

- You can add QoS rules based on the source of traffic, but not the destination (?????). Additionally, all QoS rules you add are applied to both download and upload—you can't add rules that only apply to either.

You can, but it's not obvious. The OpenVPN interface for example lets you leave the field blank. The QoS interface requires you to use wildcards like 192.168.1.* (I don't know if CIDRs actually work) to define subnets in the source IP field. Why? Who knows. See the picture above. If you know which IPs you're connecting to I would assume putting them in the field would work.

But that's what "Minimum Reserved Bandwidth" should be for... but, for some reason, it's only available for upload, and not for download. Which is yet another thing I do not understand.

Well here's the thing, it's kind of hard to tell the other network how fast to send data to you.

Hope that was helpful, not trying to be mean.

 

[Klueless]

This thread has reminded me of how much I do not know. What I do know is I have several sites. They were all on DSL which meant 15 Mbps on two and 7 Mbps on the rest. They were all failing. Set up QoS and they all started working. A dozen users and a couple dozen devices all sharing a 15 Mbps pipe? Now that's not too shabby.

(These were old N66Us so ... maybe something's changed?)

Anyway, two years ago we got a new ISP in town so we could now afford to upgrade; everything is now 100 Mbps (and better) and I no longer bother with QoS. From what I'm reading I guess I'm lucky I no longer need it?

 

[jeden]

I agree with you that this feature kinda sucks but it does work on my end. This is just a low-end RT-AC68u on Merlin 384.16. Make sure you're on the latest firmware, older ones have a bug where the upload/download clamps are reversed.

Latest firmware obviously.

It leads here: https://www.asus.com/support/FAQ/1010951

No, it leads here: https://www.asus.com/support/FAQ/1008718 — that link is broken.

It's just semantics. It actually doesn't matter if the default priority is low because that priority can still use 100% bandwidth when nothing is contesting it.
"If there are no packets being sent from high-priority applications, the full transmission rate of the Internet connection is available for low-priority packets."

It matters because if you set some device or protocol as "low" priority you think you are deprioritising it, while in fact you are doing nothing at all since "low" was the default to begin with. I think it's a bad default.

I think this is user error. ICMP packets are already prioritized (so the "The Highest Priority packet" table claims). If your packets are getting a huge delay it's probably because your Upload/Download values in QoS_EZQoS.asp are misconfigured and too high (mostly upload). You should set them so your speedtest results are slightly lower than what your connection can offer.

I already commented about this:

- Even after setting a certain category to, say, 90% of my download bandwidth (and by looking at the MB/s counter, it is certainly lowered) my ICMP traffic (such as pings) is still terribly delayed. The only way to assure it's not delayed is by lowering the maximum bandwidth of whatever category by a lot, which means I lose a lot of bandwidth; I don't have a lot of bandwidth to begin with so this is not optimal.

The max download speed my connection can offer is around 1.8 MB/s. The only way to make sure ICMP isn't delayed is by setting the max bandwidth so low that the maximum download speed becomes 1.3 MB/s. That's 72%, very very suboptimal.

(bear in mind that QoS doesn't work that well with extremely slow internet to begin with)

Then what do I want QoS for? If I had a 600/600 fibre I wouldn't be using QoS to begin with. I only use QoS to make my ADSL bearable. That's what QoS was made for.

This feature is FUBAR for me too. Sometimes it doesn't update and sometimes it attaches the wrong device to the wrong bars. Sometimes hitting the apply button fixes it. Sometimes opening up all the QoS pages in different tabs makes it work. Why does it do this? Who knows.

If you enable "Apps analysis" it sorta works, in exchange for sending God-knows-what-data to "Trend Micro".

You can, but it's not obvious. The OpenVPN interface for example lets you leave the field blank. The QoS interface requires you to use wildcards like 192.168.1.* (I don't know if CIDRs actually work) to define subnets in the source IP field. Why? Who knows. See the picture above. If you know which IPs you're connecting to I would assume putting them in the field would work.

Definitely not obvious. I might give it a try.

Thanks for your insights.

 

[jeden]

What a joke:

Lowest class is limited to 0.17 Mb/s... well guess what, it does whatever it wants.

 

[K-2SO]

I see good results with Traditional QoS. For bufferbloat control proposes. DSLReports A/A+.
https://www.snbforums.com/threads/asus-ax88u-how-to-manage-bufferbloat.63675/#post-576451
ISP specific results perhaps. No general conclusions. Asus stock firmware and Merlin.
YMMV

 

[RMerlin]

Lowest class is limited to 0.17 Mb/s... well guess what, it does whatever it wants.

Have you tried running a separate transfer with a higher priority? Last time I tested Traditional QoS (which was, what, 5 or 6 years ago?), the lower pri used all the available bandwidth, until the moment a higher priority process was fired, at which point the highest pri got most of it, and the lower pri got only what was left within established limit. I tested by running a low pri FTP at the same time as a high pri Speedtest run.

I.e. it's not built as a bandwidth limiter, it's built as a priority traffic allocation.

 

[jeden]

I haven't tried that, but if it's not a bandwidth limiter then it shouldn't say it is a bandwidth limiter.

Many of my grievances with this feature are not about the technical side, but about the texts and labels: some are not fully detailed, some are misleading, and some are plain wrong.

 

[KimN]

Any success with this? I am struggling to get tradicional qos to work properly as well, and I need to set it working.