I don't think it's tunneling the full TCP packets. I think it's extracting the data stream from the incoming TCP stream, tunneling that data, and creating a new

I don't think it's tunneling the full TCP packets. I think it's extracting the data stream from the incoming TCP stream, tunneling that data, and creating a new TCP stream to the destination on the other end of the tunnel. So basically the same as ssh -L or ssh -R .