>>34that one is impossible, even on tor.
Wrong. It's merely infeasible, at least the naive way.
Theorem. It's possible.
Proof. Every node sends pseudorandom junk (and sometimes actual encrypted data) to every other node in the network
at a constant rate. There is no way for a global passive (or even active) attacker to tell whether the data sent from A to B was junk or not without breaking the encryption. ∎