Why are you so sure it’s not a network problem? Often on these forums, duplicate ip addresses are the issue, and a network refresh and setting fixed ip addresses for Sonos devices has been the solution. Why are you ruling out that fix - have you already tried it?

You haven’t said what you have tried to fix your issue. What can be ruled out would help, if help is what you’re after?

Yup many times. Infact that is the first thing people say

You want help or you want to vent?

"vent"??  It was a "response".  Don't start jumping on me. 

Ok, to save time where we suggest stuff and you say “I already tried that”, what else have you tried? 

More and more often I find an easy justification for why I don’t even try to help people anymore, despite 15 years of an almost 100% success rate at curing these very problems.  If someone isn’t willing to listen from the get go, why even bother?  

Please elaborate. Try to convince us you're right.

With the information given so far, this has the classic fingerprints of a network issue. Prove us wrong.

Note that simple web browsing, email, and even video streaming are very simple network tasks. SONOS requires more robust network support.

Also, you and your neighbors likely have more devices on your networks than were present a couple years ago. Your dated network hardware or configuration may no longer be able to deal with this. As an example, when I scanned for WiFi access points a decade ago I might see 6-10, most of them mine. The other day I stopped counting at 70 and some of them were using setups known to interfere with nearby WiFi clients.

Here is a description of the problem.  For a couple years I only had one speaker and everything worked fine.  No problems with one speaker.  It wasn’t until I linked up several speakers to the system.  The problem is not consistent.  It may happen once a day or twice a day or I may go for a month with the system working fine before it cuts out.  What I mean by “cuts out”, the system stays powered but the sound stops.  There is no consistency to when this happens.  I have sent diagnostic information to Sonos a few times and they tell me that this will happen at times when multiple speakers are running on the system.  

So what is does your setup involve?

• Make/model of main modem/router?
• Any switches, managed or unmanaged?
• Any other WiFi access points/wireless extenders/powerline adapters?
• Wifi Channels/Channel-widths in use (Are the channels fixed)?
• Any Sonos devices wired and if so where to? (What is the Sonosnet channel set to?)
• Have the device addresses been reserved in the routers DHCP Reservation Table?
• Have you done a scan and aware of neighbouring WiFi channels in use? 

That was a poor response by the agent. I suggest that you submit again. Network issues leave tracks in the diagnostics. If there are no network issue tracks, hardware failure moves up the list of potential causes. Network issues can be intermittent. Keep a log of events. Submit within 10 minutes of an “event”.

Years ago I had a major issue in some evenings and Sunday was impossible. I slipped a copy of my log under my neighbor’s door, along with a polite note. A couple days later the log returned with annotations. Some evenings she worked out of town and Sunday afternoon she called mom. She was using a cordless phone that caused severe WiFi interference. I reconfigured my system layout to avoid her phone location and my problem vanished.

Router is connected to fiber and only used for Sonos. I only have one router.  Nothing else is connected to the router. The Sonos can be hardwired or wireless and the problem will still happen.  Works great with one speaker running. Also the distance from the router doesn't make any difference.  I only have a 750sf house 

Which model router? SONOS models? What are you using to control the SONOS system? Network switches? Other wired and wireless devices?

You say it’s not your network, but you really need to describe the network in further detail, because it definitely sounds very much like you have network issues.

You have not mentioned if you are using ‘fixed’ non-overlapping WiFi channels with a 20Mhz channel-width for example, or a SonosNet channel that is at least 5 channels away from your routers 2.4Ghz band, when wired?

How far away did you set the wired Sonos device from the router?

Plenty of questions remain unanswered here, even though you say it’s not a local network issue.

Fiber line coming into house hooked up to UniFi UDM running close to 100Mbps on upload and download 

Sorry missed a zero 1000Mbps

Most of that doesn’t make any difference. The speed of your connection to the outside world isn’t as paramount as the speed and quality of the connection between your router and your speakers. It’s pretty rare to have the error occur upstream, beyond the router

Unifi is an entirely separate thing, from my perspective. There are a lot of threads about horror stories in getting Unifi to work properly, and that’s an area I’ve stayed away from. 

@traildog,
LAN to WAN upload/download speed is not going to resolve things like SSDP (UPnP) multicast device discovery issues - There’s a common issue with default Unifi settings, especially if you have "Block LAN to WLAN Multicast broadcast” enabled and "auto-optimise network" enabled etc.

So far you’ve have not told us anything about your network that’s relevant. So I still think the network configuration is perhaps the most likely cause of your issue. You need to post the detail asked for and perhaps others here can make some worthwhile suggestions for you to maybe try.

Sorry I'm at work right now.  

Internet speed is not a critical point. When I started with SONOS I had ADSL service to the house and 100Mbps network speed. WiFi was nominally 54Mbps. Certainly, this would not serve my current needs, but I had no issues with my SONOS system.

Advertised speed is not a reliable predictor of overall performance. Recently, we changed ISP’s. The former service claimed 1000Mbps. The current service is only 500Mbps. Overall, the current service is more responsive and we have less down time.

How does the UDM connect to the fiber? What SONOS units are you using? Are any SONOS units wired to the UDM?

fiber comes into an ONT then ethernet to UDM.  Sonos is Play5 then several play3, and a Roam.  We’ve tried Wiring them and still have the original problem is all of them are playing.  The Play5 on by itself and the system works fine.

Here are some Uni-Fi considerations. STP becomes critical if more than one SONOS unit is wired to the network.

Make/Model Ubiquiti dream machine/UDM 

No other WiFi access points

No Switches 

WiFi Channel fixed 2.4 or 5 GHz either.  Band steering is forced.  

At this point no Sonos devices wired.  We’ve tried hard wired and still have the problem.  

We are aware of other wifi channels in use.

We’ve not given it a fixed IP.  The Sonos system assigned an IP address 

While you are fussing with things, reserve IP addresses for all regular clients, especially the SONOS units.

@traildog,

Perhaps see if this link will assist you with your Unifi settings and to hopefully make your network more stable for use with Sonos…

https://github.com/IngmarStein/unifi-sonos-doc