I don't think that torrent trackers are analogous to this at all, unless I'm misunderstanding how it works. AFAIK, this is essentially a proxy: you <-> hostyos

I don't think that torrent trackers are analogous to this at all, unless I'm misunderstanding how it works. AFAIK, this is essentially a proxy: you <-> hostyoself <-> someone else where all data goes through hostyoself. This is analogous to ngrok, but at file-system level rather than TCP.