Connecting to SMB server from WAN not working

I have a new Mac set up as a home server. I can use the Finder's Go | Connect to Server... from local Macs to connect with smb://my-new-server.local, but can't connect from outside my LAN. I've tried smb://myregistereddomain.net and smb://xxx.yyy.zzz.www (my actual static IP address). I have set my router to forward TCP traffic on port 445 to the server. What am I missing? Update: have now added forwarding of port 139 but still no luck connecting. Verified that my ISP doesn't block these ports. Could this be something Apple just doesn't allow? Could a remote user somehow tunnel into my LAN and access the SMB server that way? Where are instructions on doing this?