The Mport range of serial devices servers have a mode of operation that allows very quick provisioning of 2 units to create a serial tunnel over an Ethernet network.
This 'Pair Connection Mode' is easy to setup.
On one Mport configure its mode of operation to be 'Pair Connection Master'
Within the Master unit configure the destination IP address and port number to be that of the corresponding Mport.
Don't forget to hit the 'configuration' button to save your changes.
Configure the other Mport to be 'Pair Connection Slave'
Make sure its 'Local Port' is the same as the destination port you configured in the Master.
Once again, don't forget to hit the 'configuration' button to save your changes.