[Blind-sysadmins] jaws tandem behind two nat routers

Hello, I'm using jfw 10, a friend is using jfw 11. We are both behind high speed connections, I think both dsl, and behind nat routers. Under those circumstances I am wondering if it's possible to make tandem work? If so I'd like to know how as it would make remotely helping this friend much easier. Thanks. Dave.