Help upnp:rootdevice

What is this?
And why is it possible for me to see these strange things?

Right now i see 18 connections and all of them are from outside `???

• France 3
• Germany 3
• Poland 2
• Viet Nam 1
• United States 1
• /snip
• \snap

..and why can i use them??

because its the internet and these machines are open for everyone...

The one with the 88.88.x.x IP has Darwin/x86_64 as OS and uses LogitechMediaServer/7.7.4/1415167000
The one with the 83.29.x.x IP has Linux/armv8l-linux as OS and uses LogitechMediaServer/7.9.0/1488878280
The one from Viet Nam has a Synology with LogitechMediaServer/7.7.1/33735
/snip
\snap


Really????