If you think open a port for a service is not safe, like remote desktop or vnc or ftp, you can use reverse connection. By starting up forwarder, input ip , port and user of you preferred agent server, then click start to connect.
After creating your private tunnel, none can access your computer inside a local area network. If you want to connect your computer inside LAN, start Magic Router, go to Agent, input ip , port, user and password of you preferred agent server. Then start you application program, point to ip (normally 127.0.0.1) and listen port, then your remote computer will be connected.