Can my provider see that I use a VPN, and what can it do
What the provider sees with a VPN on, what it doesn't, whether it can tell Surok VPN from an ordinary site, whether VPN use is legal in Russia and how "sees" differs from "blocks".
Short answer: the provider sees that your device has a connection to some server, and doesn't see what's inside. The difference between VPN services is how much that connection looks like an ordinary one.
What the provider always sees
The address of the server you connected to, the traffic volume and the time. It's like an envelope: the address outside, the letter inside.
What it doesn't see
Which sites you open, what you write and watch. DNS queries in Surok's apps also go inside the tunnel, so even the list of sites is out of its reach.
Can it tell it's a VPN
Depends on the protocol. OpenVPN and WireGuard have a recognisable fingerprint and are visible. Surok's connection looks like HTTPS to an ordinary site: inside is the real certificate of a real site. From the provider's point of view you just opened a page.
What it can do
Block the server's address if it figures out it's a VPN. That's why we have several ways in and monitoring every five minutes: if an entry stops being reachable from Russia, we learn before users do and switch.
Is it legal
Using a VPN in Russia is not prohibited. The restrictions concern services and what you do online, not the fact of the tunnel. Our terms ask one thing: don't use the burrow for what's prohibited without it too.
And the mobile carrier
It sees the same. The extra difficulty is whitelists: some carriers let you through only to approved sites. For that there's an entry through a whitelisted network, the "Europe · auto" server: it works on mobile carriers.