QoS information

[limesn0w]

Hi, can someone please help me with how QoS actually works on the RT-N66U?

I have read the 'QoS bible' by Toastman but his specifics are for his build on the Tomato firmware.

I'm running RMerlin's firmware and I'm a bit confused.

Initially, the QoS settings are on automatic if left untouched, but if you edit them they are still automatic! Is this a glitch?

Secondly, I've been told 'Enter 85% of your max uplink to prevent starving your connection and over saturation of the uplink stream'

Does the RT-N66U know that 85% has been entered? Or does it assume MAX uplink bandwidth has been entered and proceeds to throttle 15% of the bandwidth automatically?

I'm just really confused, if anyone could help me out that'd be great

 

[lilstone87]

QoS is really a major disappointment with the asus firmware. I really wish asus would work to improve it, as its very basic, and hard to tell if its even working correctly. As setting the download limits classes really doesn't work as you would expect compared to using tomato's QoS. I asked RMerlin before about making improvements to the QoS feature, and he said he really couldn't do much. As it would require changes by asus first, making some of the big changes we might like that tomato's QoS offers.

 

[limesn0w]

I give up. QoS is broken..

After setting the uplink to 100 Kb/s and downlink to 1 Mbps with absolutely no rules or prioritys set, the router fails to cap the upload or downlink speeds, it's like they aren't being affected by QoS at all?! Someone please help me out, I must be doing something wrong.

 

[RMerlin]

I give up. QoS is broken..

After setting the uplink to 100 Kb/s and downlink to 1 Mbps with absolutely no rules or prioritys set, the router fails to cap the upload or downlink speeds, it's like they aren't being affected by QoS at all?! Someone please help me out, I must be doing something wrong.

If you have no rule, then it means all your traffic falls under the same rule, and will pretty much use all the bandwidth it can. This is what you would want.

The way QoS works is that if there is no traffic with a higher priority, then the lower priority traffic will take all the bandwidth available.

You are probably mistaking QoS for Bandwidth Limitation. The two are totally different things. QoS's goal is to ensure that priority traffic goes out ahead of lower priority traffic.

 

[limesn0w]

If you have no rule, then it means all your traffic falls under the same rule, and will pretty much use all the bandwidth it can. This is what you would want.

The way QoS works is that if there is no traffic with a higher priority, then the lower priority traffic will take all the bandwidth available.

You are probably mistaking QoS for Bandwidth Limitation. The two are totally different things. QoS's goal is to ensure that priority traffic goes out ahead of lower priority traffic.

I see! So would I be entering my lowest recorded upload bandwidth or 85% of that? Thanks!

 

[RMerlin]

I see! So would I be entering my lowest recorded upload bandwidth or 85% of that? Thanks!

Personally, I would set the upload speed at 85% of your maximum typical upload capability. For example if you have a 1 Mbits upload (and can actually reach it), set it to 850 KB.

To better understand how the QoS works, check Asus's FAQ:

http://support.asus.com/Search/KDetail.aspx?SLanguage=en&no=A96BF68D-98C9-9D26-129A-3D5E596D3073&t=2

That's where they confirm that if you have nothing else competiting for bandwidth, then the full bandwidth will be used.

 

[limesn0w]

Okay thank you RMerlin !

 

[RMerlin]

Note that specifying a lower upload capacity than what your WAN can achieve is actually recommended for Tomato. I'm not sure how different the two QoS implementations are, so it's also possible that this recommendation isn't strictly required with Asuswrt. Personally I haven't used QoS since the early days because I saw no need for it on my network.

 

[limesn0w]

Note that specifying a lower upload capacity than what your WAN can achieve is actually recommended for Tomato. I'm not sure how different the two QoS implementations are, so it's also possible that this recommendation isn't strictly required with Asuswrt. Personally I haven't used QoS since the early days because I saw no need for it on my network.

Okay I'll take this into consideration and do some testing! Do you know what's the difference between 'TCP/UDP' and 'ANY' in the rules section for QoS? I'm a little confused to what the actual differance between these terms would be - thanks

 

[RMerlin]

I just did a little test here.

I created two rules:

- One rule named Avalon, with my laptop's MAC address, and a priority of Highest
- One rule named Camelot, with my desktop's MAC address, and a priority of Lowest.

I didn't specify any protocol, to ensure that all traffic from both devices would be priorized as desired.

I started an FTP upload from both machine toward my website.

Avalon was uploading at about 350 KB/s
Camelot was uploading at 50 KB/s

(numbers are rough estimates based on values reported by Traffic Monitor - Per Device (Realtime).

Once I cancelled Avalon's upload, that left only Camelot generating traffic. Camelot's upload speed then went from 50 KB to close to 400 KB/s, now that the higher priority laptop was no longer there to require bandwidth.

So in terms of controlling uploads on a priority basis, the firmware seems to be working pretty well.

BTW - Avalon was on wireless, and Camelot on Ethernet. That also confirms that wireless devices are affected just as well by QoS.

 

[RMerlin]

Okay I'll take this into consideration and do some testing! Do you know what's the difference between 'TCP/UDP' and 'ANY' in the rules section for QoS? I'm a little confused to what the actual differance between these terms would be - thanks

ANY would also include other protocols than tcp/udp. That means GRE (protocole type 47, used by PPTP servers), ICMP, etc...