Mac OS X: Back to My Mac requires AirPort base station or UPnP-capable third-party router

The Back to My Mac feature of Mac OS X is designed to work seamlessly with compatible AirPort base stations. This seamless integration is achieved through the use of NAT-PMP (NAT Port mapping Protocol) technology, which enables your computer to automatically configure your AirPort base station to provide services between your local network and the Internet. Some third-party Internet routers use a technology called UPnP (Universal Plug and Play), which is similar to NAT-PMP. Back to My Mac works with both NAT-PMP and UPnP.