Just in case – you don’t need traffic shaping for streaming. Actually it’s vice versa – other latency-sensitive apps/services could benefit from it when you are doing streaming (which is not latency-sensitive).
And I do believe that any Asus router from the past decade is capable (computationally) of doing sub 100Mbps QoS.
Do I understand correctly that it doesn’t matter if QoS is switched on or off because it doesn’t influence streaming traffic at all?
Whhat, in your opinion, does cause the stuttering, I mean: is it something I can fix or does it only depends on the quality of the provders network?
Well, it does. But I think it’s negligible. Traffic shaping is supposed to trade some bandwidth (like 5-10%) for the sake of lower latency. It can be crucial for latency-sensitive applications (online gaming, conference calls and so on). Streaming doesn’t really require low latency.
I don’t know. Disabling QoS should improve bandwidth a bit, but I don’t think that a 5-10% bandwidth decrease would cause the shutters in the first place. OTOH, sometimes routers have a poor implementation of QoS.
Counterpoint - I mean it worked 
Just a thought here, you are streaming 4k content in this instance, if device you are streaming to isn’t capable of natively displaying 4k content, then it is being transcoded by the GPU. I have seen lesser GPU’s stutter a bit at this. Usually hitting pause on the device, then play will fix the stuttering. (buffering issues?)… just a thought.
Playing with the various settings for transcoding, was the first thing I did. However: switching off QoE gave better results.
I want to add a small remark: when I was fiddling around with the QoE settings of the router, I suddenly remembered that I activated ‘jumboframes’ in the router (without really knowing the negative effects when improperly used). I learned that EVERY single device in the network, has to support bigger frames. Turning off ‘jumboframes’ also have a big effect on streaming quality since the router was the only device where it was activated. Till than I had no clue that every network device in the chain, has to support this feature.
Starting with TrueNAS was one of the best decisions I took. It greatly helped me to understand IT better.
Thanks for the input everyone!
Every modern (from the last decade) “cabled” NIC supports it and most of the modern switches. Also, there is a variation of this statement that every device would need to be configured with jumbo frames. This statement is not actually true either.
Anyway, jumbo frames can sometimes be the cause of network issues and I’m glad that you managed to resolve them.
