While debugging a network client, I spun up Wireshark and noticed a pretty lengthy communication that my computer was having with bg.microsoft.map.fastly.net.
I didn’t find any decent information on the web so I’m documenting my research here.
This host is used to host windows updates. Your windows computer is probably connecting to check for and download updates.
bg.microsoft.map.fastly.net is legitimate Microsoft business and is harmless.