It isn't with just Airplay...none of the Sonos units will even see the network on WiFi. We're going out to one of these houses tomorrow and we'll see if SonosNet works.
It's odd that we got 2 calls in 2 days about this issue and we rarely have network problems with Sonos at all. I just wanted to be preemptive to see if anyone else was experiencing the same.
Thanks for the info!
See our Youtube page for info about smart homes, great audio and more.