@David-TP Hi David, thanks for the reply.

"So basically one is the current download rate, and the other is the maximum download rate." 

 

Thanks I understand David. I am comparing the current download rate on the desktop to what is reported as the current download rate on the Deco App. I can be downloading from server at constant 50mbps, however it is reported as ~25mbps on the Deco App. My version of Deco app has a page where I can see live what the download and upload rate is of each device on the network. Hopefully we are talking about the same thing. 

 

If I do the sum of the values on the current download rate page on Deco App whilst using the network to its maximum, it should sum to 50. It only sums to ~30 as Deco App believes the download rate of the desktop is ~27mbps + 2 mbps for the High Priority Device. In reality the load on the network is 50mbps+ as the desktop is downloading at the maximum rate of the connection. I have confirmed this by downloading a file of known size in a measured period of time. I can recreate this incorrect value on the Deco App with this device. 

 

"For the Qos service, if the TV video streaming starts first, then you began downloading the files on PC, will you still see the desktop uses all the 50m/s?"

 

Yes correct, the TV is streaming first then a download starts, though it does not matter in which order I begin, the behavior is the same. At no point does the QoS begin to throttle the connection of the desktop. The Deco App reports the current download speed at 26mbps as if Deco has throttled the connection - but the desktop is actually downloading at 50mbps. 

 

"Sometimes, when you start downing files on the PC, the data session has been established on the router already and hasn't expired yet.

Thanks a lot."

 

Unfortunately David, the behaviour doesn't change with time. I have tried deleting the desktop as a known device on the Deco App and re connecting it without luck, or do you have a different suggestion? 

Hello @David-TP,

I have uploaded a video to show you simultaneously the difference between the download reported in the Deco app and the download speed of my Windows PC.

 

At the same time as this I was attempting to stream a 4k video which is struggling on the Chromecast device which has a star signifying a High Priority Device. 

 

TP Link Deco X20 QoS - YouTube

Please note the ~35mbps download rate reported on the Deco app and the >50mbps download rate reported by Windows PC. I believe the desktop should be throttled to the download rate reported by the Deco app, but it is not and continues to consume 50mbps+ which is causing the buffering issues on the High Priority Device.  

Regards,
Tom 

Hello, Lots of helpful assistance provided by TP Link support who assisted with troubleshooting. Solution as per below from TP LINK support is to disable IPv6: Currently, the QoS doesn't take effect when the device is using IPv6, based on the captures, when IPv6 is enabled and run speedtest from Launtel to Launtel, the speedtest traffic is through IPv6 as well, that is why the speedtest results is higher than QoS total bandwidth, while speedtest via Optus server only uses IPv4, so it is respected to the QoS settings.(Launtel should have multiple speedtest servers, some IPv4 and some IPv6; while Optus should be only IPv4, that is why the results are different when selecting different speedtest servers) So currently, I am afraid you will need to disable IPv6 on Deco or on your client devices to solve the problem. At the same time, we have reported this case to R&D engineer and product engineer, we will try to work on it to see if we could optimize the function and make it work for IPv6 as well, please pay attention to our website or Deco App, if there is any firmware update, you will be able to check and update.