If you do not need remote control of the tunnel, you can also open the tunnel manually. For each tunnel that you need to create, you will need to create a client and download the supplied script because it contains the parameters related to tunnel creation (see Replacing the supplied client python script with your own activation mechanism).
To start a tunnel using the openssh, type the following:
ssh -N -i PATH_TO_PRIVATE_KEY -R IPORT:localhost:PORT_TO_FORWARD UNIX_USERNAME@FORWARDING_SERVER
Using the values from the previous example, the command would look like this:
ssh -N -i id_rsa -R 10248:localhost:22 HbN9EerI5QkA7PWGc32NItpSwICKpe@fw1.sshreach.me