Volume Control with LMS 8.0 and UPnPBridge with Sonos speaker?

Hello!

I am trying to find out how volume control is handled when I am using LMS 8.0 with UPnPBridge and a Sonos speaker (Ikea Symfonisk).
When I am using AirplayBridge the volume is simply controlled by LMS via Material Skin.
Is this the same for UPnPBridge? Or do I have to control the volume at the Sonsos device (what is not what I want)?