I've been struggling to get into games for years now. Got a new fibre line and thought I'd give it a shot again, but still have the same issues. I would not be able to connect to other players and when I do, once we get into the game it would end as soon as it starts and say that "One or more player's have left the server".
Though last night I did somehow managed to get into a Zero Hour match with 2 other guys, just ended up being very stuttery and match didnt last long.
I did port forward, firewall stuff, DMZ and static port, but nothing seems to be working. here is also my Port test results:
Using server nntest.cnc-online.net:30000
Bound to local port 55635
Bound to local alternate port 55636
Resolving hostname 'nntest.cnc-online.net'...
Resolved server host to be '188.8.131.52'
Sending client INIT from port 55635 to nntest.cnc-online.net:30000
Received server INIT 
Our public address is 184.108.40.206:55635
Sending client INIT2  from port 55636 to nntest.cnc-online.net:30000
Received server INIT2 
Our alternate public address is 220.127.116.11:55636
Sending cient START  from port 55636 to nntest.cnc-online.net:30000
Received server START 
Server extra port is 40000
Sending client PING  from port 55635 to nntest.cnc-online.net:40000
Received server PING(1) 
Received server PING(2) 
Received server PING(3) 
Received 3 pings from nntest.cnc-online.net:40000.
NAT negotiation works with your router and connection.