Question about port forwarding

[Diaoji]

I have two servers

A high-performance servers but has only an IP network (MTA server)

But there is a high bandwidth WAN IP server (Net Gate Server)

ex:

------------------port:22003------------------------------port:22005

MTA server --------------→ No.1 Net Gate Server --------------→Player

-----------------------|

-----------------------|(if No.1 Net Gate Server Can't Connet)

-----------------------|-------------------------------------------port:22005

-----------------------L--------→ Backup Net Gate Server --------------→Player

I did a SSH tunnel to forward port 22003, but can not connect to the MTA

How to solve this problem

[Diaoji]

My Server System is Ubuntu 12