I need to run a node over a cellular data connection and have managed to get hold of a couple of Teltonika RUT105 3G modems:

These devices support OpenVPN and I was wondering if it might be possible to use this to tunnel to one of my other Allstar nodes that has a regular Internet connection with a public IP address (in fact one of the sites has multiple public IP's available). 

Has anyone ever done anything like this and could give me a few clues as to how I proceed? 

I'm assuming that the node at the end of the tunnel will need two ethernet ports, one for the connection from the 3G modem to come in on and another with a different public IP for the cellular connected node to be able to use.

Does this sound feasible?

I'd appreciate any help anyone can give as I'm not at all sure how to go about configuring OpenVPN to do this having never used it before!

Many thanks,

Matt

G4RKY