Guys!
I have solved this problem after spending a lot of time researching about it.
Follow this steps above:
1) Watch this video on YouTube or search for the subject who will explain how to config your PC, step by step, to fix the error:
Link: https://www.youtube.com/watch?v=VrIqKEoYjTQ
Subject: Fix Star Wars Battlefront 2 Error Code 721 Failed to Connect to EA Servers [UPDATED]
2) Change the UDP/TCP Protocol for the following numbers:
UDP: 3659 , 9565, 9570, 9000-9999
TCP: 3569, 9946, 9988, 10000 - 29999, 42100-42200
3) I used on my PC UDP: 3659 and TCP: 3569. For me it worked fine, but if you try this combination and it doesn't work you can try other numbers.
Hope I have helped and sorry for my poor english.