QoS Download Speeds

[KaJ]

So I've had my setup for a 350mbps down/25mbps up connection for a while on my WRT3200ACM router. My method was to benchmark with QoS off, set 95% of DL speed and 95% of UL speed and then have the standard Normal/Fast classes (fast is the max 512 byte rule for bufferbloat).

When I set these rules my upload speeds would be as expected, but my DL speeds would be 25-35% lower than expected. For testing I increased my DL limit to 600mbps and re-ran a speed test, I got my expected 350mbps.

So my question is why when I accurately set my DL it never hits that speed unless I target way over my bandwidth limit?

I've lived with the 25-35% less for a while, but now I have DOCSIS 3.1 940mbps down/40 mbps up and the problem is much larger. If I set 700mbps down I only get 450mbps. If I set 1gbps down I get 740mbps down. See the pattern?

Edit: I should note that I am not using ACC.

[Lantis]

We might wait for Pbix to answer this one properly. It is nice to see the router able to push that much data with QOS enabled though

[KaJ]

It's able to handle it with bandwidth monitoring disabled. With it enabled I was topping out around 650mbps.

[KaJ]

Update: Just tried setting my download speed to 1.1gbps and I got a full 940mbps down. I'm sure I'm never going to saturate my download line and mainly use QoS for bufferbloat/upload, but I would still like to figure out why I can't set it to an accurate number to get close to full speed.

I tried ACC and it dropped my speeds down to 5-600mbps.

[mgoo]

Docsis 3.1 could imply a modem/gateway-router combo already in front of your gargoyle router. For completeness sake, what exact acc ping target did you use when trying acc?

-mgoo

[KaJ]

Docsis 3.1 could imply a modem/gateway-router combo already in front of your gargoyle router. For completeness sake, what exact acc ping target did you use when trying acc?

-mgoo

It's a modem only, Technicolor TC4400. It's using the first hop where it jumps to ~17ms from <1ms. I also tried googles DNS.

I'm fine with not using ACC though, I just want to be able to set it to 850mbps (I get around 945 with QoS off) and be able to get close to that speed. When I set to 850mbps I get ~200-300mbps less than what I set. I can get the full 945mbps if I set the QoS max bandwidth to ~1.2Gbps.

[mgoo]

Thx for clarifying on your ACC test and connection setup.

-mgoo

[gelliss]

Update: Just tried setting my download speed to 1.1gbps and I got a full 940mbps down. I'm sure I'm never going to saturate my download line and mainly use QoS for bufferbloat/upload, but I would still like to figure out why I can't set it to an accurate number to get close to full speed.

I tried ACC and it dropped my speeds down to 5-600mbps.

I'm seeing something similar on my Archer C7 v.2 router. I'm now running the latest 1.10.x build of Gargoyle. I routinely get about 118/11 on speed tests without QoS but my Bufferbloat is D or maybe C. Since adding a VOIP phone to the network I figured I'd play around with QoS.

I'm using ACC but no matter what I set the bandwidth to, I lose about half my download speed over time both on sftp downloads and on speed tests. This happens unless I set my download limit way higher than what I can actually receive and according to all I've read, I'm not supposed to do that for QoS and ACC to function correctly.

QoS seems like voodoo to me. As soon as I think I've found optimum values after running a few tests in a row, I'll do a test hours later and bam, my speeds are barely 60 down. When I reset bandwidth values way too high and I'll get full speed again.

[ispyisail]

@gelliss

Have you considered that your CPU might be maxing out?

check CPU load

[gelliss]

@gelliss

Have you considered that your CPU might be maxing out?

check CPU load

I did look at it. Here's my memory and cpu load while running a dslreports speed test that showed 80Mb down. Without QoS it's 118 down.

They don't appear out of the ordinary but then again I don't know what's considered good or bad.



What I'm seeing is fast speeds when first setting QoS but as soon as it's on for a while, the download speed goes way down and doesn't come back up again till I reset it.