Intermittent 'Unable to Connect to Sonos Product'

  • 23 November 2022
  • 8 replies

My issue is that I randomly get playback drop outs and the error log says ‘Unable to connect to Sonos product.’ The playback usually comes back and the next song in the playlist plays.

It’s been doing it to me for a lover a year and it just did it again to me tonight.

I’m currently running the following:

Sonos OS: S1
Version: 11.6.1 (build 571334140)
Hardware Version:

I’ve seen instances of this query before and the replies have always been centered around Wi-Fi. I’m not convinced as I get the same problems and I’m not running any Wi-Fi for my Sonos, which uses ZP90’s into Hi-Fi units.

I am using a wired network of Netgear Pro Gig switches, Cat5 cabling and the NAS is a Dell 720 server (running Debian Linux 10.x) which it’s absolutely rock solid for everything else on my network.

Note: I’m a network/computer professional with 30+ years in the game.



Best answer by Corry P 30 November 2022, 11:26

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8 replies

Consider the possibility that you have an intermittent hardware issue. Does the phantom always strike the same unit? If you Group Rooms, the first member is the Group “Coordinator”. All Group traffic passes through the Coordinator. If you Group, experiment with rearranging the Group.

If you have a BRIDGE in the system, assume that it is causing trouble until proven otherwise. The BRIDGE power supply should put out slightly over 5V. Less than this there will be intermittent, difficult  to describe issues.

Thanks for the feedback Buzz.

No bridge in the system.

I’ve only really noticed this issue on the unit in the lounge as it’s where the main hi-fi is so I will swap it out with one of the others and see if the problem persists.

Last night I got a second dropout error, this time “network connection speed insufficient to maintain playback buffer” which seems unlikely for a Gig network.

Just for reference when copying files to/from the server I get circa 115MB/s throughput.

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I wonder if this is a duplicate IP address issue, please see my post here.

Thanks for the suggestion but definitely not a duplicate IP.

Userlevel 7
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Hi @hodge555 

Welcome to the Sonos Community!

I suspect either STP (Spanning Tree Protocol) or multicast flooding to be the issue.

I therefore recommend you get in touch with our technical support team directly, who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

As you are experienced with networking, however, enabling IGMP snooping on your router and/or managed switches should solve the multicast issue, if present, and this Configure STP settings to work with Sonos help page should assist you with STP.

I hope this helps.

Thanks for the suggestion Corry P.

In this case my 3 Netgear ProSafe GS108 switches are unmanaged and there is a single Class C IP range LAN involved but I will check out multicast and STP on the network.

I put an old Fluke in my network and looking at the live network protocol mix we generally are seeing 37.2% to 60% IP and 9.8% to 17.8% SAP-BPDU (BPDU is Bridge Port Data Units hence STP traffic).

Of the STP traffic the majority, like 99%, came from my Sky Q box with only a tiny amount from the 3 Sonos ZP units. Looks like the Sky box is sending out a frame about every second.

The Fluke is only a 10Mb unit (682 Enterprise Lanmeter) but it never showed anything above the minimum utilisation.

As an experiment I throttled the link down to 100Mbps between the switch in the lounge with the “problem” Sonos and the switch in my office which in turn connects to the switch in the garage where the server is. I then played the Sonos (flac files typically 40MB each) and at the same time pulled a 3GB file across the network from the server, same source for both, so that I could artificially max out the network. I got a consistent 97Mbps on the laptop and the Sonos played fine. The Fluke didn’t show any real difference in the protocol mix.

Then about 10mins later, after testing pulling a file at the same time but still with the 100Mbps network, the Sonos errored again with a “network connection speed insufficient to maintain playback buffer” in the middle of a song.

The server is a Dell 720xd with 2x Xeon X5-2695v2 CPUs, 256GB RAM, 12x 4TB SAS 7.2k in RAID50, 2x 1GbE bond0, running Debian 11 (Bullseye).

Looking at the network monitor on the server I get 11.3MB/s when pulling a large file and playing Sonos and about 250KB/s just playing the Sonos. 

The network utilisation for the Sonos seems quite low so is the issue the Sonos ZP not having a big enough buffer to really handle flac sized files?

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Hi @hodge555 

FLAC has a bitrate of 1411Kbps, whereas mp3 and other similar codecs tend to max out at 320Kbps, so you can definitely encounter issues playing FLAC when you don’t with other formats - the buffer fills up quickly. This tends to be due to signal strength or interference, however, which obviously won’t be affecting you.

ZP90s are old however - if you have crossfade or shuffle activated, you can reduce the load on the device by deactivating these options. This could mitigate the issue.

Please recreate the issue and while playing, submit a support diagnostic and reply here with the number given and I’ll take a look for you. Thanks.