Roon RAAT and "An audio file is loading slowly"

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There's an update posted by John from Roon on their forum.  To save you following the link:

Hello All,

We understand the frustration being expressed by many of you in this thread and we share in your disappointment that this issue is yet to be resolved. Our goal here at Roon Labs is to enrich people’s lives with the best music playback experience in the world, not to frustrate users with cryptic error messages and network troubleshooting.

In April, we reached out to Devialet with the results of our testing in the QA lab as well as our summarization of the survey we put out to affected users. We offered to assist their team in any way possible and expressed desire to see this issue resolved with confidence. Their response was that they were aware of the issue and were investigating internally. We did not receive any further requests for assistance from their team, aside from an inquiry on how we recommend users should handle temporarily working around the issue. We followed up with them on July 1st and were met with the same response.

One thing to keep in mind: The majority of Devialet Expert users do not encounter this behavior during Roon Ready playback. This always adds complications to the troubleshooting process as well as the targeting of any potential fixes.

Due to the noise being by made our users, we re-started our own investigation a few weeks ago and plan to bring the latest findings to Devialet in the coming days. Our current understanding of this issue is that it is triggered by an issue in the ethernet stack on the device and is not related to the RAAT or Roon Ready implementation.

Bottom line: This issue can only be resolved by Devialet. We have offered our technical assistance to their team. We plan to reach out with further technical feedback with hopes that we can assist their investigation and expedite a fix to affected users.
In the meantime, our recommendation for users experiencing this issue is to use the device’s WiFi connection if possible. Some have reported that placing Expert Pro behind a 100mbps switch enabled use of Roon Ready playback without encountering the slow media error, however this “fix” is not endorsed by the Roon team as we cannot guarantee this will resolve the issue.

Going forward, we will be sure to do a better job communicating whatever updates we do have regarding the issue. I will follow up in this thread after we have reached out to Devialet.

[David A]

You beat me to it, just saw the post from John a few minutes ago.

His response makes sense to me, it's a Devialet issue and not a Roon issue. I hope Devialet can see sense and accept assistance because I think we're in for a long wait for a fix if they don't.

[mdconnelly]

As I indicated in my response to John on the Roon thread, I'm puzzled when he says that the majority of users are not experiencing this problem. I can readily believe that the that the majority of users do not stream hi-res content on a gigabit ethernet network and therefore may never see this issue. That's great. But if he really means that the majority of users that do stream hi-res content at gigabit speeds are not experiencing the problem, than I want some of whatever they got. I've seen a few posts here from users that are not having this problem on their gigabit network streaming hi-res. I am both envious and curious.

But John's bottom line ... "This issue can only be resolved by Devialet. " seems pretty clear. I do believe Devialet will eventually reallocate resources to this, but I suspect we won't see it for awhile. Until then, I'll likely continue to resubmit Devialet tickets asking for an update every few months. I just don't want to see it fall through a crack. Like a dog with a bone, I love my Roon/Expert Pro combo too much to let it go.

[daniel.avasilichioaei]

I just made the same test as per my post #261, but this time for 10 Mbps network connection via cable.
10 Mbps connection seems to be the only one acting correctly, having no peak (much larger traffic) at the beginning of the track, and also having no network traffic fluctuations.
Updated test results are here attached.

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@daniel.avasilichioaei Well, if the connection is running at 9.8 Mbps steady state and the link is 10 Mbps there is no headroom for a peak during start-up...

...also I wouldn't regard the throughput peak in itself as incorrect behaviour. Do you have any evidence that it is the root cause of the problem?

[K4680]

Hello, after some report the user have the problems or not, but actually only two sources of error remain (according to the statement of Roon)?

1. The network of the user?
2. Defects, software bug etc. (CI board) with some users?

I myself have 3 people using the Devialet Pro (220, 440) and no one has problems. Everyone uses Roon Nucleus or Ron Rock, as well as Tidal and Qobuz (playing 24bit/192kHz)!

It can be crazy sometimes.

I hope there will be a solution for the affected user soon!!

[Antoine]

Not sure if it was part of the Roon survey they sent to affected users but it could be a good idea to ask those users for the first 6 digits of their Devialet’s MAC address (these indicate the manufacturer of the ethernet hardware). IF some users are truly affected and some not, different internal hardware could be a cause. If there’s no correlation to MAC address then it must be the user’s networks or computers (I hope that that’s not the case since the number of variables in that case is of course near to infinite) since the software running on the D’s is the same in all cases. Edit; in that case Devialet would probably try to create a workaround based on a setup in which they can replicate the issue and hope it fixes the issue for all affected.

[daniel.avasilichioaei]

I just made the same additional tests as per my previous posts, also direct cable connection, but this time using another network card (3rd one - an USB card): LINKSYS USB3GIG.
I tested multiple scenarios:
- Using network card with USB 2 port, and with USB 3. On both USB 2+3, the network connection speed is set to 1000 Mbps. This is the “technical” connection speed.
- Using auto negotiated speed 1000 Mbps, manual speeds 1000 Mbps, 100 Mbps and 10 Mbps.
The bug is occurring on USB 3, but it is not occurring on USB 2. On USB 2 everything works fine: no “Audio file loading slowly” error, and no network traffic fluctuations. This is for RAAT protocol. AIR protocol is working fine in any circumstances, configurations and settings.

Even “technical” connection speed is 1000 Mbps for both USB 2+3, USB 2 is limiting the “actual” connection speed (data traffic) to less than 1000 Mbps. This is the only network card that allows me to test different actual connection speeds over the same “technical” connection speed.

As per my limited networking knowledge, and results of all tests that I performed, my deduction is that RAAT protocol over Ethernet is generating communication errors (and package resend). This is happening at any network connection speed (including 10 + 100 + 1000 Mbps). Still, this has a user perceivable effect only when large amount of data is involved (e.g. 192kHz audio files).

[thumb5]

@daniel.avasilichioaei - your test comparing the USB 2 and USB 3 "Gigabit" network interfaces is an interesting one.  If I understand correctly, the negotiated link speed is 1 Gbps in both cases but because USB 2 can't support that data rate the effective bandwidth is limited to less than 1 Gbps.  Furthermore that limit on the bandwidth seems to avoid hitting the error condition.

Together with what I saw in the WireShark traces you posted earlier that suggests to me that there's some limitation in the Devialet when Roon starts the TCP connection.  It seems that although the Devialet is advertising a large window size in fact it can't cope with the initial inrush of data if Roon sends it at 1 Gbps, whereas it is OK if the incoming data rate is less than that.  This suggests to me that packets are being dropped in the Devialet's Ethernet device driver or possibly the network stack because for some reason it can't keep up with the initial rush of incoming traffic.

This could be a CPU power limitation although I think that's unlikely as the i.MX6 used on the CI board normally has enough horsepower to handle a 1 Gbps network interface.  My best guess based on these symptoms would be that the Ethernet driver or network stack is not correctly configured (number/size of buffers, descriptors, etc.).  If that is the case then hopefully a firmware change should be able to fix the problem.

[K4680]

New Roon Nucleus announced!

https://community.roonlabs.com/t/when-wi...able/70577

(At the end of the chat)