The infamous "network issue" or something else?

Greetings to everyone on the best forum I have the pleasure to be a part of.

I’ll begin by stating that I have changed absolutely nothing for the past year in my network which consists of an Xfinity cable modem connected to a set of Orbi satellites. I have occasionally had to reboot the system and/or reinstall an app or two but the network has served me well across all of my audio, video, computing and even automobile needs (both our cars are at least mildly “smart” and have their own apps which connect to the same network).

Today my Mosaic app has simply stopped working on both my iPhone and my Mac computer! It was fine early this am and then just not any more. Now, I simply get the spinning “Looking for Devices …” screen under device selection. At the same time my Roon app is happily connected to my Rossini and playing music on my main system. And the rest of my network is working just fine.

BTW, I do reasonably often see the spinning “looking for …” on my iPhone but it usually lasts for a few seconds and then all is well. Not today.

Does this mean I simply have to reinstall Mosaic on my devices? Is this enough information for a diagnosis? Any help would be welcome.


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You need a response from a network expert or try dCS directly.

I am unfamiliar with your network hardware as I can only find USA availability. However googling Orbi indicates that this is a mesh system and such things are known as causing discovery issues with Mosaic ( what you are suffering).

So no quick solution from me but , yes it is probably a network issue and, no, you don’t need to reinstall Mosaic.

[email protected]

Thank you Pete for your prompt response. You have already added to my knowledge as I did not know that mesh systems, which is indeed what my Orbi is, do not play well with Mosaic!

Also, I waited a couple of hours and retried Mosaic on my iPhone and it now works.

I did absolutely nothing else beyond waiting. Music continued to play in my system through Roon and I went about my daily tasks.

I am guessing that you are right Pete and these are simply the handshake issues between Mosaic and my mesh network you wrote about. I will wait for any others or dCS support to weigh in as appropriate.

I’m a little bit with Pete on this:

  • Doubt reinstalling is necessary or will help
  • By all means restart the iPhone and the Mac (and the Rossini for good measure)
  • What IP address is ther Rossini showing (you can check via the front panel)?

[edit: sorry, crossed in the ether]

I have been using a Orbi mesh network in my set-up for over 7 years. Once I got passed some initial set-up issues my system has been rock solid for years. I seldom use Mosaic for listening as it is light years behind Roon but when I occasionally use it for Tidal I don’t have any issues.

I am not sure how you have your Orbi connected but to get around my teething issues I inserted a switch which is hardwired to the main Orbi unit. My SGC i5 running Roon is connected to the switch. My Vivaldi Upsampler is also connected to that switch via A short Ethernet cable after a long run of Optical from the switch. This is for my 2-channel room.

For my whole house set-up one of the Orbi satellites is hardwired to a SonoS module which outputs Roon to the integrated amp driving speakers in 8 other rooms


Mesh networks shouldn’t cause any problems if configured like yours. The key points are that the:

  • Internet router/source (for streamed content)
  • Media Server (e.g. Roon Server)
  • Any local files (e.g. NAS)
  • The renderer/endpoint (networked dCS unit)
    are all interconnected with wires.

The control points (remotes) should be fine connecting over mesh as they are not involved in the actual delivery chain, however even this has caused problems in odd cases where, for example, a mesh network had been “tacked on” to existing home network and the user ended up with two DHCP servers (so not a mesh issue per se).

Mesh can work absolutely fine - and then quite suddenly not. The problem is that it is vulnerable to lots of factors that can change dynamically and quite outside the user’s control or knowledge which can make troubleshooting intermittent problems, if they occur, quite difficult.


Thank you again, all.

I was one of the early programmers for and users of the Cray supercomputer so computers and technology by themselves don’t scare me. I set up my home network myself and did my best to keep it simple, so I’d understand it and could trouble shoot it as needed.

Yet I’m afraid that some of what you network experts write here goes over my head. I’m quite out of my league these days with some of the discussions!

Anyway, here’s my simple setup which I’m going to try and explain as clearly as I can so hopefully some of you experts may be able to give me specific, personalized advice. Here goes …

1: I have “the Internet” piped into my home from my cable company (Comcast Xfinity) to a Motorola cable modem

2: I have a very short Ethernet wired connection going out of my cable modem to my ~7 year old Orbi mesh router base unit

3: This router base unit then communicates wirelessly to 4 satellite units placed around the home

4: From one these Orbi satellite units I again have a short, wired Ethernet connection to my Rossini Apex unit. (All Ethernet cables are from Blue Jeans Audio)

Though my Orbi units are 7 years old, when I test the speed of my Internet connection using the Orbi app, it shows as 900 Mbps for downloads, 24 Mbps for uploads, and a ping speed of 8ms.

I believe these are excellent speeds and I have almost no issues watching movies streamed to my TVs or simply accessing the Net or whatever else. It literally is only the Mosaic app which often gives me the “Looking for devices ,” prompt, which earlier today wouldn’t go away for a few hours. Which, in turn, led to my original post.

I also have connected a Synology NAS to the same Orbi satellite which the Rossini is connected to but have not yet got around to using the NAS for anything other than storing my photographs. My Roon base (not the right terminology I know, is currently my Macbook pro, though I do plan on shifting to the Synology NAS at some point). Finally, I’m not sure this is relevant, but I use NordVPN for internet access.

Do you still recommend a switch somewhere to help matters? If so, how and where? Or should I do something else? Thank you again for any help. Cheers

Given your explanation that nothing has changed for months and it suddenly stopped working, and with just the information you’ve provided so far, it’s nearly impossible to guess what could be wrong. :thinking:

Generally speaking though, it’s not a good idea to have a dCS component sitting on the other side of a wireless network (mesh or otherwise). The problem is not one of raw throughput (“900 Mbps” in your stated case), WiFi6 (or 7) has more than adequate throughput, the real issue is the significant packet jitter involved in the air-interface (note: completely different from the traditional synchronous interface jitter associated with HiFi), and usually results in unreliable operational experience in any kind of streaming.

If I’m not mistaken, dCS (and even Roon) will reject any support request where their components are sitting on the other end of a WiFi link.

That said, I do have a couple of additional comments - apologies for the length of this post, please feel free to stop reading if it’s TL;DR :laughing:

There are broadly 2 categories of problems when it comes to HiFi networking;

  1. Device discovery issues - the usual “Mosaic can’t find my Rossini”… “UPnP Server disappears from Mosaic”… “Roon remote can’t find Roon Server”… etc. etc.

  2. Streaming services quality issues - like, “Tracks keep skipping during Tidal playback”… “my Desktop Qobuz App works perfectly but Qobuz on dCS is intermittent”… etc.

First thing to note is that comparing one networking application that works, to another that doesn’t work, usually isn’t very helpful because in networking, different things typically work differently even if the end outcome is similar. For example, just because the Qobuz Desktop App works perfectly, doesn’t mean that Qobuz on a dCS component will; the two work differently, including (and especially) the Servers on the Internet that they access! (Yes, might be hard to understand or believe, but it’s true).

Secondly, to point 1. above, the mechanics of how each application discovers the dCS component is quite different - Mosaic discovering dCS, Roon discovering dCS, Tidal App (Direct) to dCS, Spotify App (Direct) to dCS, UPnP Server discovery by dCS, etc., they almost all work differently!

When it comes to device discovery, in most cases, Multicast is a key aspect of how devices are actually discovered. Even among professional networking practitioners, Multicast can be a bit of a “black art” because there are so many dependencies that could impact it working properly, including specific timers and timeouts (which is why there’s often a change in behaviour “after some time”).

Not only that, depending on the application involved, the Multicast specifics applied for the discovery can be quite different for different applications! For example, the way that Tidal Direct discovers a dCS component on the home network is based on mDNS (formerly “Bonjour”), which is totally different from how the dCS component discovers a UPnP Server on the home network, which is based on SSDP; the mechanics of the two couldn’t be more different. This is also why WiFi mesh systems are less than ideal, because some don’t handle Multicast properly or can be intermittent in its Multicast support.

With respect to 2. above, most people imagine that the Internet is static, when in fact the Internet is changing all the time. In many cases due to outages, but also due to capacity upgrades etc.

Your dCS component’s streaming path across the Internet to a Qobuz server last week could very well be different than it is today! And there’s no guarantee that the route today is any better (or worse) than it was last week (here’s a link for a “birdseye view” of instantaneous outages on the Internet)

The default behaviour of most folks is to blame dCS, when in fact the probability that a bug has suddenly emerged in your dCS hardware/software is infinitely small compared to the probability that something has changed on the Internet that is affecting your Streaming service.


Now I know why I’ve been having issues with my MS Office365…
Thanks @Anupc !

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Your Orbi set-up is similar to mine. As I indicated earlier I had plenty of teething problems with the Orbi Mesh in my initial set-up about 7 years ago. Orbi support was terrible. I eliminated all of my problems by adding inexpensive switches after each Orbi Master and satellite and that is what I plug all my devices into. My Network “thinks” these devices are hardwired to the network and I have absolutely no issues with connectivity. I have considered upgrading to the latest Orbi gear but I shudder at thinking I might have to reconfigure something that is working so flawlessly.

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THANK YOU (!) both Anup and Jim.

Anup for the masterclass in networking issue categorization, written clearly enough for even me to understand. And Jim, for a practical solution which I can hopefully implement!

In that context, Jim could I trouble you to point me to the switches you use; I will simply replicate exactly what you did, or perhaps a newer version of the brand/type you purchased, and hopefully obtain the same results.

And Jonathan, like you, I too now have a plausible explanation for the occasional hiccups I have with wireless streaming - “packet jitter in the air interface”!

My already high appreciation of this special forum has only risen as a result of the exchanges of the past day.


I have the same/ similar issue with ubiquiti mesh network. In my case i think although the handshake from ap to ap should be seamless and the dcs system is hardwired overlap from the access points and my phone moving constantly with me it sometimes needs to look for the appropriate location. Conversely my ipad which rarely leaves “ my room” rarely has an issue

Here is my set-up. Xfinity Internet——> Motorola Modem —Ethernet–>Orbi RBR50—Ethernet—>Trendnet TEG-S51SFP.

Small Green Computer i5 running Roon with 2GB storage —-Ethernet—> Trendnet TEG-S51sffp———> optical fiber cable about 30’ run to lower level music room—-> SGC Optical module coverts back to Ethernet. —-1m —> Vivaldi Upsampler.

In addition Orbi RBR50 —-> wireless to Orbi RBR50 #1 satellite —-Ethernet—->Trendnet switch Non optical—-Ethernet—SonoS Connect output —->RCA stereo—-Krell integrated (which passes Roon Output on to 8 other rooms)

If you changed nothing I’m betting something did change that was done by one of your hardware or software providers. I’ve used a mesh network (TP-Link) for many years and as long as I had access to my dCS network, specifically the Vivaldi Upsampler, I’d never had an issue with the Mosaic app running. It would sometimes fail to properly connect with the dCS, so I’d kill the app and launch again.

However, it might be worth the trouble and pain to power off all network associated devices and then power each, one by one, starting with your cable modem. Then your primary Orbi mesh and then all the other Orbi devices. And then the Rossini. Finally launching the Mosaic app.

The software or firmware on one or more of the network devices may have changed and performing this process may clear up things. If it continues to occur it might be that whatever changed in firmware/operating system/etc may be at fault. Memory leaks, or other anomalies may have cropped up. Then it’s time to contact the individual companies involved.

Kind of you to write this thorough piece. And I take your point about it being too simplistic to ‘blame’ dCs. However …. Mosaic is the only app that ever ‘hangs’ for me. I never had issues with the Naim app in a previous generation of my set up or for that matter when connecting directly with any streaming music service (I’ve tried them all at one time or another) or with Sonos which I use in other rooms mainly for simple news radio listening (I’ve had plenty of other issues with Sonos but not this annoying ‘hang’ that the Mosaic app does). I’ve implemented all the suggestions in here - including creating a separate WiFi network only for use with a dedicated controlling iPad etc etc and still this hanging issue persists. It is incredibly annoying and despite the technicians pointing out it is only 2-3 seconds (and it’s my network that is the issue, which I don’t believe) it is still nonetheless very irritating. Especially as on about one in 20 times it does it, it fails to reconnect completely and I am often left with music playing I want to pause or change and having to reboot the Bartok to correct it.

Now that I think about it Nick, you are right. It is ONLY Mosaic that does it for me as well.

I too have Sonos in a separate area and also BluOS in a different area yet and neither of them have this hanging issue. I hadn’t thought about it the way you did and it is, at a minimum, interesting that it’s only the Mosaic app on my iPhone that does the “hanging”!

I haven’t had the time to do the fixes Jim et al suggested here yet, and I do hope they are fixes! Fingers crossed.

Nick, I don’t disagree that Mosaic can be annoying at times compared to the user-experience of other applications. It’s slightly tangential to my previous post in this thread, but in my view there are two issues going on here with respect to what you raised;

  1. Due to the software architecture of Mosaic Control, briefly described in the post below (which I won’t rehash here).
  1. The occasional hang/crashing of the streaming Compute board within the dCS platforms - most times from bugs that go unreported as people just reboot their unit and don’t investigate what caused the issue. Or the compute board reboots itself and comes back after a minute or so, during which time people think it’s a Mosaic Control connectivity issue, when in fact it’s Mosaic Control not being able to connect to the streaming board until it’s done rebooting itself.

At the end of the day, it’s not uncommon for a high-performance product to be slightly more finicky than your average mass-market consumer stuff. Just the nature of things. I’m sure other high-end solutions are not without their own foibles :laughing:

In reply to your point 1 above, I was rather hoping that creating a separate WiFi network in the house just for the iPad that controls the Bartok; with that iPad literally only used with Mosaic and with sleep mode turned off it would remain connected and not hang, but still it does it!
Hence me still pointing the finger somewhat at dCs here. You’re right - it is only 2-3 seconds but it is still infuriating.
I agree in the world of high end tech things can get a bit finickity but this is surely avoidable!?

Just seeing this post from 8 days ago.

FINALLY someone putting into words what I have been experiencing since day one with my Rossini.

At least I now know it is not unique to my particular unit. I also now understand the reason.

I do, however, believe that problems of this type do not belong happening on what most of us believe to be end game units in the digital playback world.

During my 9 year use of a Linn Klimax DS (it is still here and continually has its internal hardware kept up to date) the unit and it’s streaming board have been bullet proof having NEVER exhibited any glitches.

Thanks @Anupc for finally explaining what I have been experiencing.



Yes it is. there are occasions when things do go wrong but that is true of all digital equipment. Look at yesterday’s worldwide issue with Microsoft. However regular drop outs with Mosaic should not happen.

As has been pointed out as Mosaic operates in a stateless fashion, if it is switched off then connection will be lost. This is different to losing connection and loss of program during normal operation.

You should have gathered from the numerous threads and postings on this subject that configuration of your router is normally the cause of this and that it is easily fixed. You have not mentioned doing anything along these lines. BTW,

If literally interpreted this cannot work. You cannot have a separate network excursively for the control point. Bartok ( or the network board otherwise) and the control unit have to be on the same network.

The most common issue is that the router or other switch has software settings set as defaults by the supplier which cause issues with Mosaic. What may be a quick fix is for you is to access the software of your router/switch via your browser. Look through the settings menus and deselect IGMP snooping.