Yes my pc is wireless. I have a wifi extender too. I can connect it via cable and try that way. Should I do anything different? Or just connect it and see if it works?should I revert the port forward to port 16000?
Thanks!

Hey there,

Do you have a lan port on your computer/ laptop. If yes, try a direct connection using a cable.

If that does not work, call your ISP and ask them to open port 16000 on your network. If they have no clue what you are talking about, ask if you could be connected to their network operations department or get a contact number of someone in that department if possible.

You probably may need to get a static public IP (your ISP may charge for it). Since you have a symmetric NAT you are more likely to need a public IP that does not change so that your port forwarding on your router can take effect.

So I called my isp again and this time they actually helped me. They talked about changing something in my ip. Whatever,the network diagnostics is positive now I'm so happy.
Thanks a lot for your time guys!

They basically opened the port at their end which you obviously couldn't have done from your side. Never the less I am glad its working fine for you now.