What system information does the router and provider see when I'm connected from an android / pc?

Question

Computer networks

In general, the essence of the issue is in the title.
Thank you in advance for your help!

Answer 1

When surfing through the mobile network, the operator can transfer your IMEI and phone number to http sites through header substitution. Once, I went to the site, and spam got out in full screen with my number.

Answer 2

MACAddress, internal IP address.
Well, he can see traffic.

Answer 3

If the provider sniffs traffic, it can pick out the user-agent for http requests.
He sees ttl - you can determine whether you are walking straight or through the router.