Without port forwarding, remote access will not work. Why? Because when your computer sends a request for information to WAN (out to the Internet), it is initiating the request from inside your LAN. The only reason the data is allowed back into your private network is because you sent for it. Port forwarding doesn’t need an outbound request.
Tomato firmware has a feature called “DDNS” which makes remote access a breeze. Dynamic DNS updates your public IP address automatically. This way, you can reach your home network without having to remember your public IP address. And since most home networks have a dynamic public IP address, Dynamic DNS solves that problem.