long running ssh function without tying up a term?

Hi. Got a situation where I have a machine A connecting to machine B, by way of a reverese SSH connection. I also want to have a machine C be able to connect to machine B, and then connect to machine A.. My issue/question.. the initial reverese SSH from A-> B needs to be created, and then left alone, to run as long as required.. might be hours/days... but on machine A, I don't want to create a term, just for the sake of running the reverse SSH.. I'd like to have a way of running the reverse SSH, and then not having the term stick around.. I've looked at Screen/nohup but couldn't see a way to make this work.. Thoughts/comments appreciated. Thanks sshpass -p pass ssh -R 2000:localhost:22 user(a)foo.com -p 50122 -creates the initial reverse ssh, but it leaves the opened term/connection as well -I'd like to basically create the connection/process/port on machineB, and but machine A's connection in the background so to speak, as opposed to having a term session sitting around. thanks