While this article is still a great description of how to wire your Sonos network using BOOST devices, we have since replaced the BOOST devices in our home. Now we have an advanced network configuration that takes advantage of Sonos Beams, as described here.

Recommended Sonos Network Configuration

Even if you have a multi-access point Wave 2 Wireless AC WiFi network, I recommend connecting your Sonos speakers as follows:

1. Ethernet1, else
2. SonosNet 2.0 wireless network (“Boost” mode), else
3. your existing WiFi network (“Standard” mode).

This will reduce the likelihood of audio drop outs and network loops, particularly as you connect more Sonos speakers and/or run them in pairs. Relatively few homes have Ethernet wired throughout. The more Sonos speakers you have in your home, the less likely that you have an Ethernet drop in exactly the same location as where you wish to place your Sonos speaker. Therefore, most–if not all–of your Sonos speakers will use some form of WiFi connectivity: SonosNet or your private home WiFi network.

BOOST Mode and SonosNet

BOOST mode uses SonosNet 2.0, a proprietary wireless mesh WiFI network operating in the 2.4Ghz band.2 It includes MIMO and utilizes 20Mhz wide channels. SonosNet is optimized end-to-end for audio delivery to Sonos devices.3 If you use SonosNet (BOOST mode) exclusively, both your music and Sonos speaker control will be multicast to each room (for stereo pairs, the left speaker unicasts to the right speaker). This permits you to stream multiple lossless audio streams throughout your home.

If you use Standard mode, then only the Sonos control information will be multicast. Audio will be unicast to each speaker, which isn’t scalable if you have many Sonos speakers.

If at least one Sonos One speaker can connect via Ethernet to your router, then you do not need to buy a separate hardware device like the Sonos BOOST to run SonosNet. Just plug in at least one speaker via Ethernet to your home network and reboot all your Sonos speakers. You can confirm that your devices are running on SonosNet by going to About My Sonos System in the desktop app. For each Sonos speaker, it should say WM:0.4

SonosNet uses Spanning Tree Protocol (STP), a network protocol that builds a logical loop-free topology. STP permits only one active path on the network between two devices. If you connect your Sonos speakers to your Ethernet or WiFi network and your networking gear support STP, then I recommend enabling that feature. I provide more details about how I implemented this across a Ubiquiti Unifi aggregator and secondary switches here.

Sonos BOOST Hardware Device

The Sonos BOOST hardware device is a dedicated access point, running SonosNET. Like an Ethernet-connected Sonos speaker running in BOOST mode, it creates a wireless offload network for your Sonos speakers. Using a BOOST device frees you from placing a Sonos speaker near an Ethernet connection.

Contrasting the BOOST device with a Sonos speaker running in BOOST mode, the BOOST device:

• contains 3 wireless antennae for 360 degrees of coverage and significantly more range
• has “enterprise grade wireless performance”, and
• has “advanced wireless interference rejection”

The BOOST device does not have any smart or managed switching capabilities. So, you may still need to pair a BOOST device with a separate managed Ethernet switch if you have a significant amount of non-Sonos multicast traffic in your home.

Evolution of My Sonos Network Configuration

Initially, I had only two Sonos One smart speakers, each in different rooms. I used Standard mode, connecting them to my Wireless AC WiFi home network. As I added more Sonos speakers, I encountered occasional audio drop outs, particularly noticeable with paired speakers and particularly with lossless audio. Typically, dropouts and buffering are a function of how much data you are streaming on your wireless network. Running more concurrent audio streams or running higher bandwidth streams like lossless audio places a greater burden on your wireless network. This is particularly true in Standard mode because it unicasts audio.

One of my Sonos One speakers was close enough to one of my WiFi access points’ Ethernet port that I could plug it in via Ethernet. This offloaded all my Sonos audio traffic to the separate SonosNet WiFi network. However, my Ethernet-connected Sonos One was at the far end of the house. This meant that audio traveling from there to the other end of the house had to travel a number of hops across other Sonos speakers. Here is what my network looked like using only an Ethernet-connected Sonos speaker.

Colored cells (green, yellow or red) represent an active wireless connection. Grey cells means that SonosNet isn’t sending data wireless between the two units. The colors in the left column represent the ambient noise conditions: ANI levels correspond to the cell color codes. 0-3 is green; 4-5 is yellow; 6-7 are orange; 8-9 are red. The colors in the cells represent wireless tunnel strength. The inbound and outbound numbers go up to 64. Lower numbers are worse.

Now, I have purchased three Sonos BOOST hardware devices to feed my sixteen Sonos One smart speakers and a Connect:AMP. I attached each Sonos BOOST device via a managed Ethernet switch to our router. I ensured that the Sonos BOOST devices are configured for an empty 2.4Ghz channel to minimize RF interference.

Comparing the before (Ethernet connected Sonos One speaker in BOOST mode on one side of the house) versus the after (centrally located BOOST device), the improvements are relatively modest in terms of the number of yellow cells.

But, adding a second Ethernet-connected BOOST device makes a significant difference in the number of green cells.

At three Ethernet-connected BOOST devices, we have reached the point of diminishing returns for our house. Note that all three of my BOOSTs are Ethernet connected. It is also possible to run the satellite BOOSTs wirelessly. However, I found that, when I did so, the other two BOOSTs weren’t used by the Sonos system at all. This is because Sonos tries to minimize the number of wireless hops across devices. With this many Sonos speakers, it makes sense to use Ethernet backhaul and multiple BOOST devices.

Understanding the Sonos Network Matrix

Beyond the red/yellow/green color codes, here’s how to decode the data presented in the network matrix:

• Signal strength (field strength) is the measure of the signal between your Sonos components. The higher your score the better.
  
• Noise floor is defined as the sum of all signals–other than the one being measured–including unwanted atmospheric and incidental (man-made) noise. Man-made noise includes your neighbor’s WiFi networks, Bluetooth devices, microwaves, cordless telephones, baby monitors, and security cameras. In the network matrix, you can view the noise floor for each Sonos speaker. The lower your noise floor (as measured in negative dB), the better. For example, a noise floor of -115 db is better than -85 db.
• OFDM ANI level is a measurement of how well your Sonos components are coping with interference in your wireless environment. The lower your score the better. 0 is best, 9 is worst.

Multicast Flooding and Sonos

One issue that I struggled with was intermittent dropouts of rooms or paired speakers within rooms. I could play a single Apple Lossless-encoded stream from my Music Library in only 2-3 rooms before I had issues. Party mode always failed. The Sonos Escalations team confirmed that you should be able to play at least three separate lossless streams simultaneously.

Since the issue wasn’t RF-related, we narrowed it down to non-Sonos multicast traffic on my home network. I have a number of Google Cast enabled devices that use multicasting. Sonos heavily relies on multicasting both for group control and audio streaming. The Per-TXQ and Latency fields on this screen are critical: http://boost_IP:1400/status/proc/ath_rincon/fullstatus.5 Any multicast traffic in excess of 143 (Per-TXQ field 0) causes the buffer to be dumped and your Sonos system to behave unexpectedly.

The solution is to place a managed Ethernet switch between the router and your Sonos BOOST device(s). If you cannot run each Boost device to a dedicated port on the managed Ethernet switch, then you are better off running a single Ethernet-connect BOOST for reach (even with more yellow cells) and keeping your Sonos system ‘walled off’ from the rest of your home network. A good “starter” managed switch is the Ubiquiti Networks US-24 24-Port UniFi Managed Gigabit Switch with SFP.6 After installing a managed Ethernet switch, you should configure it as described here.7

Tips

Wireless Coverage

• I recommend putting a single Sonos One in as many rooms as you listen to music before spending the same money on Sonos One pairs in fewer rooms. This permits you to use voice control in more rooms. Additionally, this enhances the coverage of your SonosNet mesh network if you are using a BOOST configuration without a dedicated BOOST device.

Avoiding Wireless Interference

• Make sure that you place your Sonos BOOST device at least 2 to 3 feet apart from your wireless router or access point. Do not place your BOOST device on metal.
• Make sure that your Sonos BOOST is operating on a different 2.4Ghz channel than your home network’s access points.
  • I recommend manually specifying the channels on both your router and Sonos, rather than using “auto”. Use only channels 1, 6 or 11
  • Use a WiFi survey tool like WiFi Explorer.
• For more network configuration tips, I recommend reading my companion article: How To: Optimizing Your Multiple Access Point, Wireless-AC WiFi Network.

Network Management

• To review your SonosNet network status, visit the web site running on one of your Sonos speakers: http://player_IP:1400/support/review
• If you started your Sonos network in Standard Mode, then switched to using Boost Mode, I recommend removing your WiFi network’s credentials from your Sonos system. In the iOS app, you should do a network reset (the button is hidden below the iOS keyboard) under Advanced Settings.

Resources

• Discussion in the Sonos Forum about this article8
• Sonos Software Release Notes (for the current version)
• How to Set Up SonosNet (“BOOST” Mode)
• How to Switch from Standard to BOOST Networking
• Wireless Interference and Sonos (video)
• Sonos BOOST (video)
• Sonos and the Spanning Tree Protocol
• How to: Enhance Audio Streaming Performance With the Sonos BOOST
• Sonos STP Switch Settings
• Music Meets Wireless Mesh Network

Updated on February 23rd, 2019