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by kpil 3084 days ago
I also have three Chromecasts and occasionally 7-8 mobile devices that are connected to them in multi-AP network. I have mostly Sony devices and I think they have a rather aggressive powersave profile.

The last 3-6 month or so, the mobile devices have been losing connections to Chromecast while playing, and the network have become markedly more flaky also for other devices.

I actually got a Chromecast Ultra with an ethernet connection in case the wifi was bad, but it didn't really make a difference.

At some point a D-Link AP that is also the main router started to hang at least once per day, occasionally every 5 minutes. I installed Lede on it in order to rule out hardware problems - and then it stopped crashing at which point I stopped bothering, but I suppose the hardware can still be cooked.

I've noticed that the network occasionally is really slow for a short while - I managed to measure the speed to an external provider to be around 4-5 mbit/s instead of 100, but I haven't considered the possibility that it's my own network that goes bananas.

The WAF is declining, but it's so much junk that can go wrong so it will take a considerate amount of time to debug.

Edit: I must say though, that I expect my routers and APs to survive 100.000 packages...

1 comments

The unnecessary flood of multicast packets these Google devices send is causing your AP to drop to its lowest speed and broadcast those packets.

Its the equivalent of having an 802.11B client that only syncs at 1Mbps and is constantly downloading. There is no airtime left for anyone else!

Things you can try: Block 802.11G and lower clients (increases your minimum WiFi transmission speed), convert multicast packets to unicast (LEDE is apt to support that), or throw the chromecast in the dustbin!

The scary part is that it takes highly involved HackerNews readers to possibly understand what's happening. Most regular folk are going to just think, Wi-Fi got flaky again.
Hang on, if you're converting multicast packets does that mean only one device is receiving them?
The WiFi AP handles unicast packets differently than multicast packets.

So on a network with N devices, you just convert one mulicast packet into N unicast pakcets.

Because multicast packets are sent with the slowest possible rate, this actually speeds up performance as long as N < 20.