Providing your site works fine from inside your network you need to configure your router to "Port Forward" all incoming ftp traffic to your ftp server 192.168.1.102 see your instruction manual for how to do that. To connect from the outside world you will have to provide your users with the IP address that your ISP provides you with. This address should be static. If not then your address will change regularly which will give your users big problems in finding you. Most ISPs will upgrade your service to provide you with a static address. Do be aware though that if you have a static IP address it is easier for a hacker to find you.