topic Re: Airplay dropouts on 802.11n in Access Points - Indoor and Outdoor

Airplay dropouts on 802.11n

casper_pedersen — Fri, 29 Oct 2021 11:46:55 GMT

Hi,

I got an R610 with 200.9.10.4.243 which does not give me any problems in general, except for one thing: airplay

I have tried almost everything, incl. for the AP to have 0% connections on 2.4GHz to force connections on 5GHz.

I stream from my iPad Pro which always connect with 802.11ac which is streaming to an Raspberry Pi 4B+ running RoPieeeXL (Airplay).

My problem is; when the Raspberry connects with 802.11n my iPad will loose the connection to the RPI within 20-30 seconds after I start streaming, when I then use the Troubleshooting (Unleashed) which can force the RPI to connect with 802.11ac the airplay connection will work for hours.

What I do understand is why does the connection get cut when the RPI connects with 802.11n and not with 802.11ac ?

Any recommended settings I should try out?

This is driving me crazy, as this is how I listen to radio ....

Re: Airplay dropouts on 802.11n

casper_pedersen — Fri, 29 Oct 2021 13:47:13 GMT

I have to add to the above, that there are dropouts even with the RPI is connected with 802.11ac. Only difference is that it "only" happens every 5-15 minutes, and with ac the connection is not lost.

Re: Airplay dropouts on 802.11n

eizens_putnins — Fri, 29 Oct 2021 14:03:14 GMT

You have the worst possible combination -- open source client, closed source Apple server, and very sensitive service. You can just hope that you are not the first making this weird mix...

Re: Airplay dropouts on 802.11n

casper_pedersen — Fri, 29 Oct 2021 14:16:08 GMT

@eizens_putnins you're possibly right. I used to have Unifi nanoHD's - and never had a problem with this specific thing - many other problems though.

For me it looks as if the Ruckus resets something every so many seconds, which causes the connection to be broken. But what it is, that is the big question.

Re: Airplay dropouts on 802.11n

eizens_putnins — Fri, 29 Oct 2021 14:50:06 GMT

As much as I understand, currently Airplay 2 uses multicast, so you probably need to look in multicast configuration. Airplay 1 was unicast, I think, and had bigger buffer, so it was much more stable in bad conditions.

AP usually resets something connections when requests are incorrect -- which easy can be a case with both Apple (which has own opinion about all standarts) and RPI (which may not follow any standards). It could play better with UBNT, as they have very basic software, without any additional services or checks, and no interest to comply closely with any standard too, which in some cases may be a positive thing, actually.

But most probably in fact in current situation UBNT would have even more problems, as generally Ubiquity AP are not too good.

But thing may be as simple as unfortunately chosen WiFi channel and interference -- try to change a channel, make spectral analyses and look for interference sources. Look into logs -- what exactly happens, when connection is dropped? Run sniffer on RPI to see what packets are lost or whatever else happens...

Re: Airplay dropouts on 802.11n

syamantakomer — Fri, 29 Oct 2021 15:01:25 GMT

Hi @casper_pedersen,

MDNS is used for service discovery, so if you are not able to discovery devices when using Airplay then issue could be related to multicast to unicast conversion.

You can disable this from WLAN settings >> Advanced Options >> Directed multicast threshold >> Set it to '0'.

If service discovery is working fine and issue is with sharing the content, then it will need in-depth troubleshooting including OTA captures on AP and from clients when you face the issue.

As explained by eizens_putnins, it could be related to interference as well so try selecting good available channels as well.

If nothing is working and you are not able to fix it, open a support case.

Re: Airplay dropouts on 802.11n

casper_pedersen — Fri, 29 Oct 2021 15:29:06 GMT

Hi @syamantak_omer, @eizens_putnins,

Thanks, it's not multicast (mdns) as the service is still seen - it's just drop outs on the audio stream.

But it's not the shairport-sync (airplay deamon) - when I steam from a wired computer (iTunes) everything is fine.

That makes me believe that it could be one of two things:

- communication between two devices connected to the same AP (doubt that).

- iOS / iPadOS having an problem (I'll play around with that over the weekend).

Thank you for your help so far.

Re: Airplay dropouts on 802.11n

casper_pedersen — Mon, 01 Nov 2021 08:18:24 GMT

Hi @syamantak_omer, @eizens_putnins,

I found the problem, I had enabled Self Healing, Background Scanning, Client Load balancing and Radar Avoidance Pre-Scanning.

Switching these thing off solved the problem, Airplay is now working again without any problems.

Thanks.