If it was for the later, I think Wide-Area Bonjour (DNS-SD) is a good substitute. Bonjour handles port-forwarding via NAT-PMP or uPnP as well service discovery.

If it was for the later, I think Wide-Area Bonjour (DNS-SD) is a good substitute. Bonjour handles port-forwarding via NAT-PMP or uPnP as well service discovery. I have a bias or two though (see profile).