How to determin best Multicast Rate setting

Dear forum experts,

can someone please explain to me, how I can determine on how to best set the Multicast Rate setting via AP → Wireless SSID → “[My SSID]” settings on a Balance One or AP One AC Mini?
I have no idea, what the different values mean and couldn’t find anything suitable in the PL router manual or forum about it.
In my household I have 2 AP AC one Minis under central control of my Balance One delivering 2,4 Ghz and 5 GHz WIFI to a bunch of Apple Hardware (like iPhones, iPads and Apple-TVs) and Sony TV, IOT-Devices and a Web-Cam.
I have no idea how I can find out, what is the best setting for this and would appreciate some guidance.
Is Maybe MCS31/…54M the best and fastest for modern hardware? See screenshot.

Didn’t find any guide or documentation regarding it.
These 2 links are the only guides I found regarding this subject in the world wide web:
So for me it sounds like → the more Legacy Values (6M << 54M), the better it is?

My understanding…

The best is multicast filter / off because multicast takes up air time that others could use. So if it’s not being used by something… you don’t want one device spewing multicast and eating up air time. This could break things like multi room audio on Alexa.

2nd best, is the default setting it’s at… use the new encoding scheme because that takes less air time and the smallest size possible … 6M

3rd best… If you need more than 6M worth of multicast… ie you are streaming video over multicast in your house and the stream is let’s says 22M, then go increase the multicast rate to only what’s needed as to minimize the air time required.

That was my understanding after reading up on it a few weeks ago. If I’m wrong hopefully someone can correct me.


I can confirm that if you turn on multicast filter for your WLAN SSIDs on APs or Balance One, your Apple Homekit devices are not able to communicate with each other furthermore.
IGMP Snooping on is no problem and helps reducing traffic.

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That would be expected given they are using mDNS / Bonjour to communicate and discover each other, snooping just ensures that only the AP with clients needing the multicast group gets the group sent out of it. :slight_smile:

As for changing the multicast rate, frankly don’t bother - in a small home network you are unlikely to need to unless as has been mentioned have some specific high bandwidth multicast application running.

For the why that knob exists, this appears to be a pretty good blog on the subject and saves me typing it all out (including multicast to unicast conversion which is how we deal with this in larger, modern networks if dropping it outright is not an option!).