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Greetings everybody,

I would highly appreciate your potential help and suggestions on my problem here.

 

Situation:

  • Sonos Arc(wired) with Sub gen.3 and 2 x Ones. All show as “WM0” in the report.
  • Gigabit fiber internet at home.
  • Provider’s router has WiFi disabled and i use Ubiquity Unify UAP-AC-LR (wired to the router) for a 5ghz WiFi. No 2.4ghz radio enabled.
  • Signal and speed of Wifi when Sonos is not engaged is around 350-400mbps on mobile and wireless devices (Speedtest).
  • PC with ethernet cable always shows around 950 mbps in speedtests. A very good speed.
  • Xbox, Sonos, LG TV, EuFY dorbell system, are all connected to a TP-Link managed switch via ethernet.
  • I have no audio drops when Sonos is playing. It works fine.
  • Distance from the Arc to the Unify AP is 3 meters.

My problem:

When i play Sonos, either with Spotify or TV sound, the speed of the WiFi drops dramatically. Sometimes i have download speed at 70mbps and the upload to 30mbps and sometimes i have my download around 30mbps and the upload around 70mbps. Some other times i have below 30 Mbps in both download and upload. It really fluctuates, but always in a degraded speed.

When i turn off Sonos, the speed comes back to normal.

I tried changing Sonos WiFi channel in all possible settings but no luck.

I also un-wired the Arc and used the home WiFi to connect with Sonos. With this, the problem becomes worse. I experience speeds around 7-8 mbps! So i rolled back to “wired” connection.

I called the support and submitted the diagnostics. They found no issue and they said that its normal to consume the bandwidth since Sonos is streaming to sub and Ones at the same time. They could not help me further.

 

I find this speed degrade unjustified and i would kindly appreciate any help/suggestions you might have.

Cheers

This sounds slightly odd. The Arc’s own 5GHz, used to support its satellites, is frequency agile. It should switch to a different channel if it encounters congestion.

The next time you have a problem, point a browser to http://x.x.x.x:1400/status/proc/ath_rincon/status where x.x.x.x is the Arc’s IP address. A few lines down is the HT channel, in MHz. See how it compares with your Ubiquiti channel allocations.

Are any of the satellites close to an AP?

Hi Ratty 

it looks like HT is 5220, see below  

For Unify AP it shows as :

Channel: 40

Bandwidth: 80mhz

not sure how to compare it though  

 

the subwoofer is 2 meters from the Unify  

the surrounds are 5 meters far and the Arc is 3 meter far  

 

 

 

 

 

contents of /proc/ath_rincon/status
Debug info for INFRA mode at 18362558 Mode: INFRA (sonosnet) Operating on channel 2412 Home channel is 2412 HT Channel is 5220 RF Chains: RX:4 TX:4 RF Chainmask: RX:0x0F TX:0x0F Max Spatial Streams: RX:4 TX:4 Noise Floor: 0 dBm (chain 0 ctl) Noise Floor: 0 dBm (chain 1 ctl) Noise Floor: 0 dBm (chain 2 ctl) Noise Floor: 0 dBm (chain 3 ctl) PHY errors since last reading/reset: 5603910 Region: 2 Node F0:F6:C1:E0:10:4B - FROM 00 00 : TO 00 : STP 00 : MODEL 32.1: KEY -1 00 00 Node 38:42:0B:55:97:3B - FROM 00 00 : TO 00 : STP 00 : MODEL 28.2: KEY -1 00 00 Node 38:42:0B:55:95:BB - FROM 00 00 : TO 00 : STP 00 : MODEL 28.2: KEY -1 00 00

5220MHz is channel 44. https://en.wikipedia.org/wiki/List_of_WLAN_channels

So basically it’s currently in the middle of your Unify’s AC. The Unify could be having to throttle back to 40MHz, possibly 20MHz, at times. That said, AC should sense and adjust on a per-packet basis, so it’s a bit surprising if the Unify is so adversely affected.

As an experiment have you tried shoving the Unify up to the DFS channels? The AP should take a minute or so before it begins transmitting, whilst it senses any potential channel occupants (weather radar, etc).

Hi Ratty

i think with your suggestion to switch to DFS channels the issue is resolved. Many many thanks for your tip.
I switched to DFS channel 52 with 80mhz bandwidth and high transmit power. 
all my speed tests now are going well. Even with Sonos working. 
ofcourse I will keep monitoring the situation the next days

 

Is there any downside to switching to DFS ? Is this the best practice?

 

I also have another same Unify in the attic. This is in not in DFS. It’s on Chanel 36 with bandwidth 80mhz. 
 

shall I switch that to DFS as well?? I have no Sonos in the attic (yet) though. 
 

much appreciated with thanks

 

 

Units using the DFS channels are -- as the name implies -- instructed to change frequency dynamically as and when they detect priority users (weather sensing, the military, etc). As well as having to RX for a short while before enabling their TX, the APs must keep monitoring the channel and jump if the need arises. In my experience an AP on a DFS channel may sit there happily for days/weeks then suddenly re-appear in the unrestricted 36-48 sub-band. You’ll just have to see how things go.

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