It doesn't sound like it is tunneled within SSH --- rather, it uses SSH as a sign-in method to launch mosh's own protocol handler that uses its own socket. Onc

It doesn't sound like it is tunneled within SSH --- rather, it uses SSH as a sign-in method to launch mosh's own protocol handler that uses its own socket. Once mosh launches, ssh exits. Since it uses ssh for authentication, it has eliminated some of its peer-review problems.