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JonFo

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The buffer bloat seemed highest on the test during upload test

IQ Router Quality A , mentioned nothing about buffer bloat.

....
2nd run on IQ router gave me an A +
Upload is typically where the worst bloat is encountered, and as I discussed above, the pacing of the ACKs is critical to what the Netflix server thinks your stream needs in terms of resolution.
If there is a shift back and forth on resolution, that's where I think the Netflix App bug gets exposed.

Your line is pretty good, as A and B ratings mean latencies are typically below 200ms, and mostly below 100ms. That is usually good enough for streaming.
Hopefully applying the QoS change I recommended to your Amplify will get that traffic to precede regular traffic.

Got to run, so I'll reply to other topics later.
 

Robert D

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Upload is typically where the worst bloat is encountered, and as I discussed above, the pacing of the ACKs is critical to what the Netflix server thinks your stream needs in terms of resolution.
If there is a shift back and forth on resolution, that's where I think the Netflix App bug gets exposed.

Your line is pretty good, as A and B ratings mean latencies are typically below 200ms, and mostly below 100ms. That is usually good enough for streaming.
Hopefully applying the QoS change I recommended to your Amplify will get that traffic to precede regular traffic.

Got to run, so I'll reply to other topics later.
Haven't looked into doing that QoS setting yet, but will later. That should be an option on my Amplifi router, or is it somewhere on the modem? I never mess with the modem, so if its on there it will probably be more challenging for me to do. I'm not even sure how to access it on the web. My Amplifi router has a nice app on the phone I use.

Ive been thinking about something. Most of the problems I have are late at night and I'm the only person in the house using the internet. I guess that wouldn't really matter if the upload had a bit too much buffer bloat? Nobody else in the home is competing with me for bandwidth.
 

Robert D

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Upload is typically where the worst bloat is encountered, and as I discussed above, the pacing of the ACKs is critical to what the Netflix server thinks your stream needs in terms of resolution.
If there is a shift back and forth on resolution, that's where I think the Netflix App bug gets exposed.

Your line is pretty good, as A and B ratings mean latencies are typically below 200ms, and mostly below 100ms. That is usually good enough for streaming.
Hopefully applying the QoS change I recommended to your Amplify will get that traffic to precede regular traffic.

Got to run, so I'll reply to other topics later.
Looks like my router only has QoS for wireless devices. It says anything wired get priority.

 

JonFo

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Looks like my router only has QoS for wireless devices. It says anything wired get priority.
Yeah, that pretty lame of them.

So the only way to mitigate bloat would be to deploy something like an IQrouter (with WiFi off) between the modem and the UniFi base, then switch the UniFi into pure AP mode (I think they call it 'bridge') and you'd have well-managed traffic.
But your line is borderline good, so I'd pin my hopes on Netflix fixing their App.

BTW- for those reading: If you are getting D's or F's for Bufferbloat when wired to your router, you should check out the IQrouter, makes a world of difference in those scenarios.
 

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So can I rule out buffer bloat and overall connection issues? This is at 6pm too and thats probably around peak time for usage in our area, people returning from work etc. I usually stream shows late at night and the connection is a bit faster then. Cant imagine buffer bloat being high at night if its not high now?
It is likely it is bloat-related, as even mild bloat (as in your case) seems to expose the issue. JLasher and I, with very low/no bloat, do not have the problem.

And Bloat (added latencies under load) can and will manifest in a transient manner. You do not need to fire up 12 connections and saturate them for >10 seconds, it can all happen in bursts that measure in <1 second.

Streaming is accomplished, ironically enough, not with a steady stream on one or two connections. It is done by sending bursts of traffic and then waiting for a second or two, then another burst for a second or two, etc.
These inbound bursts generate a burst of outbound ACKs, and those pile up in the outbound queues, and without effective traffic management, will potentially suffer delays of >200ms, which is where the bloat appears.

To the streaming service, it now looks like your line was not able to keep up with the rate of the last burst, so it downshifts either or both the send rate or the quality in the payloads.

BTW- The reason streaming is done with bursts is to combat bloated lines, as if they were to go steady-state on a bloated line, the bloat just grows until the connection fails. Using bursts, the build-up in the queues can drain.

Bloat will vary throughout the day, one of the patented features in an IQrouter is the ability to dynamically adapt the Traffic management settings throughout the day. And man has that feature been exercised this past year! Lines that used to be rock-solid now need adjustments at 3pm, then again at 7:30, maybe back up at 10, then back down at 11pm. It all depends on what not only your network is doing, but often what's happening in the neighborhood.
 
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JonFo

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Im at a loss as to what is causing my Netflix sound issue on my Apple tv. Any ideas Jonfo?
It is very, very likely the Netflix App. Nothing Apple can do about that.
Hopefully, the recent tvOS update forced App makers to release updates and Netflix will address this issue.
 

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It is likely it is bloat-related, as even mild bloat (as in your case) seems to expose the issue. JLasher and I, with very low/no bloat, do not have the problem.

And Bloat (added latencies under load) can and will manifest in a transient manner. You do not need to fire up 12 connections and saturate them for >10 seconds, it can all happen in bursts that measure in <1 second.

Streaming is accomplished, ironically enough, not with a steady stream on one or two connections. It is done by sending bursts of traffic and then waiting for a second or two, then another burst for a second or two, etc.
These inbound bursts generate a burst of outbound ACKs, and those pile up in the outbound queues, and without effective traffic management, will potentially suffer delays of >200ms, which is where the bloat appears.

To the streaming service, it now looks like your line was not able to keep up with the rate of the last burst, so it downshifts either or both the send rate or the quality in the payloads.

BTW- The reason streaming is done with bursts is to combat bloated lines, as if they were to go steady-state on a bloated line, the bloat just grows until the connection fails. Using bursts, the build-up in the queues can drain.

Bloat will vary throughout the day, one of the patented features in an IQrouter is the ability to dynamically adapt the Traffic management settings throughout the day. And man has that feature been exercised this past year! Lines that used to be rock-solid now need adjustments at 3pm, then again at 7:30, maybe back up at 10, then back down at 11pm. It all depends on what not only your network is doing, but often what's happening in the neighborhood.
Why doesn't video quality go down, and 5.1 audio is unaffected? Seems like an issue specific to dolby atmos .
 

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It is very, very likely the Netflix App. Nothing Apple can do about that.
Hopefully, the recent tvOS update forced App makers to release updates and Netflix will address this issue.
I also heard small audio artifacts on HBOMAX a couple of nights ago. Just 2 seconds or so of a static sound over some or all of the channels. I couldn't tell what speakers did it because it was over so fast. It never came back. Was watching the remaster of The Matrix Revolutions in dolby vision with atmos.

So small issues with hbo too. Only Atmos problems, 5.1 is fine.

Netflix has the sound cut out entirely like mute was pressed.
 

JonFo

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I forget the exact count of variants a streaming service will have for each movie, but focusing just on the main features being discussed, a movie or show needs the following, in descending order of size:

4K UHD / DV + Atmos
4K UHD / DV + 5.1 (for systems with no Atmos)
4K + Atmos
4K + 5.1
1080p + Atmos (rare, most services tie Atmos to 4K)
1080p + 5.1
lower level resolutions 720, 480, usually only one audio option, typically 5.1.

My guess is what Netflix is doing is oscillating between these two:
4K UHD / DV + Atmos
4K UHD / DV + 5.1

It downshifts the audio 'resolution' before it downshifts to non DV (as you all see, that handshake takes a while). So audio is the first thing to be sacrificed.
But it's not that huge (at least compared to the video), as the max DD+ Atmos data rate is 768Kbps per the spec. A 5.1 soundtrack is typically in the 300 to 500Kbps range.
And who knows, they might also have good, better, best encodes for the video, while keeping with the 4K DV standard, allowing them to shave size (in exchange for less video quality).

Other services possibly calibrate their choice based on unit history and current performance and stay locked into a given choice and either allow buffering or stream failure if line quality dramatically shifts during playback.
 

Robert D

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I forget the exact count of variants a streaming service will have for each movie, but focusing just on the main features being discussed, a movie or show needs the following, in descending order of size:

4K UHD / DV + Atmos
4K UHD / DV + 5.1 (for systems with no Atmos)
4K + Atmos
4K + 5.1
1080p + Atmos (rare, most services tie Atmos to 4K)
1080p + 5.1
lower level resolutions 720, 480, usually only one audio option, typically 5.1.

My guess is what Netflix is doing is oscillating between these two:
4K UHD / DV + Atmos
4K UHD / DV + 5.1

It downshifts the audio 'resolution' before it downshifts to non DV (as you all see, that handshake takes a while). So audio is the first thing to be sacrificed.
But it's not that huge (at least compared to the video), as the max DD+ Atmos data rate is 768Kbps per the spec. A 5.1 soundtrack is typically in the 300 to 500Kbps range.
And who knows, they might also have good, better, best encodes for the video, while keeping with the 4K DV standard, allowing them to shave size (in exchange for less video quality).

Other services possibly calibrate their choice based on unit history and current performance and stay locked into a given choice and either allow buffering or stream failure if line quality dramatically shifts during playback.
That's along the lines of what I was thinking. Only weird thing, for me on Netflix I don't just lose the 4 Atmos channels and drop to 5.1, I lose all sound for 10 seconds or more and then it returns to atmos.

I've not tested atmos after the new Apple patch. Maybe it helped?

Anyone know a web page that shows what was in the latest update?
 
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