Roon RAAT and "An audio file is loading slowly"

[Manfred]

It just looks like auto-negotiation is failing, and we‘re ending up with a half-duplex link.

You can have Full Duplex and 100 Mb.

[Manfred]

Further to my initial response to @Manfred, his response, and my immediate reply above, I'm going to toss out a theory for comment.

The Theory:

We have 2 separate issues going on.

First, some "background" points I've noticed that I think are relevant"

- Networking problems manifest themselves in things like dropouts and there's a lot of different networking issues that can cause dropouts. Roon themselves identify several general things and several other things specific to certain network devices that can cause problems with Roon that can show up as dropouts.

- RAAT uses TCP/IP and more data is transmitted in the process than gets transmitted when using other protocols such as AIR.

- More data is transmitted with high resolution files than with lower resolution files.

- The maximum amount of data the Devialet will receive is therefore going to occur when we stream a 192/24 file (highest resolution a Devialet can handle) using RAAT.

- Finally this problem crops up with RAAT but not with other networking protocols, and with ethernet but not with wifi. Other connection methods (USB, coax/optical, AES/EBU) aren't affected because they don't involve the network. This is purely a network issue, purely a wired network issue.


So, we've got a pool of Devialet owners using ethernet connections to their Devialet's, some of whom are having problems and some of whom aren't. Some of those have networks with some of the network issues identified by Roon (eg @Manfred got improvements when he changed the auto negotiation and flow control settings of his switch for the port his D220 is connected to) and some of those have networks without those issues present.

And we know that some of the pool of Devialet owners using ethernet connections get this problem and some don't. Of those who get it, some report problems with files of lower resolution than 192/24, some only with 192/24.

I think it's possible that:

(a) the Devialet has an issue handling the amount of data involved with a RAAT stream arriving over a gigabit connection.

(b) people with networks which don't have other issues of the sort identified by Roon who get the problem only notice it with 192/24 content or mostly with 192/24 content and rarely with lower resolution content.

© people with networks which have issues of the sort identified by Roon notice dropouts with 192/24 content and with lower resolution content but the reason they're noticing it with lower resolution content when they didn't notice it before is because the higher data amounts being transmitted with RAAT are sufficient to trigger dropouts due to the network problems and the lower amounts of data being transmitted using AIR aren't.

(d) both the Devialet issue in (a) and the separate networking issues in © show up as dropouts. There's no way of telling by listening whether a dropout is caused by the problem in (a) or the problem in © but they both get regarded as the same issue because both started to occur with the implementation of RAAT.

Note that we've had at least 1 person claim that RAAT is unusable, period, even at 100 MBPS while others find dropping the connection speed to 100 MBPS solves the problem. I think dropping the connection speed to 100 MBPS is a workaround solution for the Devialet problem in (a) but it doesn't address the network issues of © which require changes to the network settings.

I think the Devialet specific problem in (a) relates to the speed at which the data is received (I suspect that wifi reception is either occurring at lower than gigabit speed or that there's a difference in how the Devialet handles wired and wireless signals which  result in the issue not occurring with wifi). I wondered whether it may be a buffer size problem but if 192/24 works with a 1000 MBPS connection and not with a gigabit connection then buffer size can't be an issue because the same amount of data is going into the buffer. Reception speed seems to be the only obvious variable.

That leads me to predict that a fix for the Devialet problem won't solve all of the problems for some people because they will still need to fix their network issues which didn't start to show up prior to the implementation of RAAT.

For those having problems, especially problems at lower resolutions than 192/24, then try reducing the connection speed to the Devialet to 100 MBP but if that doesn't clear things up then start looking hard at your network for issues of the sort identified in Roon's Best Networking Practices document and fix them. If you've got a managed switch and changing settings doesn't help, then try an unmanaged switch.

Finally, a possible explanation for why this didn't show in Roon and Devialet's testing: they did their testing on networks with settings that didn't create problems so they didn't notice anything at resolutions less than 192/24. You don't test to see if something works over a network that is known to cause problems because you then wouldn't be able to tell whether the problems you notice are the problems with your network or problems with what you're testing. If you've already told users about those network problems, and Roon had because they affect all network streaming, not just RAAT, then you've got a right to expect that people will already have looked after those things. With 192/24 content I've noticed issues immediately on one occasion and only after a period of problem free play of well over an hour on another occasion. Maybe they didn't listen long enough at 192/24 for the problem to crop up in their systems. There are always time constraints on testing anything.

(a) I don't think that is the problem. If autonegotiation is enabled and it fails it can set the connection to half duplex. This then can really slow down the network. E.g. printing a document in my network with the autonegotian failure documents come out of the printer after 10 min!

[Manfred]

I started my Devialet Journey with D170 now D220Pro CI. With D170, AIR, Win7 everything works fine up Win 10 was introduced. With D220 Pro and the CI module, UpNP did not work - stuttering, AIR with JRMC did not work unstable, stuttering and also as I started with ROON, ROON RAAT did not work "Pause" during playback, until I found the following solution for me:

I have a managed Linksys switch, where my Devialet is connected to (see attached architecture overview figure). 


If I configure my switch according to the following table everything works UPnP, AIR and RAAT:

I also get it running with Auto  Negotiation enabled and with Auto Advertisement set to 100 Full Duplex on the Devialet port and Flow control enable. But that seem to flood the network (all ports all blinking heavily), the switch was not anymore reachable, I had to unplug the power chord. So I currently use the solution described in the table.

[mdconnelly]

OK, it's been 4 months since Devialet released their latest OS/firmware that was to support RAAT. In Devialet's timeframe, that's not all that long, but perhaps it's time for another ticket or two if for no other reason than to hopefully get some feedback on what this issues are. Hard to imagine that Devialet (or Roon) have not figured out the problem, even if they aren't ready to release a solution. Then again, who knows how much of a priority this is to them.

[David A]

It's also now less than a week to the 2 UK dealer events that Matthieu Pernot will be attending and we can hope that he will be asked questions on this and we'll hear back what he has, and hasn't, got to say.

[thumb5]

We'll have to wait a little longer than that; the events are in July (according to my diary, at least).

[David A]

You're right. For some reason I've been thinking that they were in June.

There goes one good idea :-(

[thumb5]

Not to worry. I'll make sure I ask about RAAT over Gigabit Ethernet while I'm at the event.

[David A]

Many thanks. With luck, however, you won't have to ask because it will be fixed but I'm not certain that I'm feeling lucky.

[audio_engr]

I'll make sure I ask about RAAT over Gigabit Ethernet while I'm at the event.

Thank you!