[eddythompson80]

I'm guessing people commenting on UPnP vs mDNS implementation are mostly referencing this post https://www.linkedin.com/pulse/what-happened-sonos-app-techn...

But it wasn't just a move from UPnP to mDNS with everything else remaining the same. They also moved to HTTP/WebSocket instead of UPnP eventing, added encryption.

While most complaints in this thread about the app all say "it's sluggish", with the initial release of S2 many had their systems that worked perfectly fine with S1 undiscoverable with S2. At the time all the advice on Sonos forums, Reddit, etc was "First check your router and make sure mDNS isn't disabled". Which caused a lot of people to have a kneejerk reaction of "wtf is this mDNS shit and what was wrong with the "old reliable UPnP"

[jauntywundrkind]

HTTP/WebSocket relies on a stateful connection! Man that strikes me as so not smart!

Comedically, UPnP was also HTTP, but not as stateful as websockets. Often httpu, http over UDP. And for service discovery, httpu over multicast, pretty much like mdns. I'm surprised that s2 would have broken, given that I'd expect s1 to also need multicast. Maybe Sonos setup a pinhole router via upnp-igd, so devices could talk to each other inside the network, even if multicast was off? It's be interesting to know if any upnp-igd rules were created in s1.