Something similar was also asked here, but there was no answer:
I recently purchased a Smart Things Hub and was setting it up at home. I wanted a doorbell sound to play via my Sonos when a button was pressed (using the Iris Smart Button).
It all works fine using the Speaker Companion app, however I noticed the latency is quite bad from when the button is pressed to when the Sonos plays the sound (4-5 seconds or more). However, looking in the Smart Things app, I see the button press registered almost instantly. Therefore the latency must be somewhere within the SmartApp calls, however where exactly I have no idea
-how would I go about seeing where the latency is? eg. all the network requests that happen to make the sound play and the time each takes.
-would creating a Smart App that accesses a sound file on the local network help with latency? or does the Hub cache any binary files it fetches over the network anyway?
-how is playback on Sonos actually accomplished? does this also route via the cloud or does it send playback locally to the device?