1. i see you put only UDP (port: 7777).
2. Try to make a "test2" and put also TCP port: 7777
3. save them.
4. Locate your ip here: http://whatismyipaddress.com/ (copy your ip adress)
5. Go to SAMP Browser, and then add server: yourip:7777 in the browser.
6. You got online your server.
If you got any other issues post it here and we will help you! I had TP-Link in the past.