Instructions
Restart the game. Sometimes, you may simply have a poor connection and need to reconnect to the servers. Additionally, you may be on the same server as someone else experiencing lag, which can affect your own gameplay.
Try playing the game during off-peak hours. The more people playing at the same time, the more likely you may experience connection issues.
Add an exception to your firewall settings. Read the documentation for your specific firewall since all programs are different. Avoid disabling your firewall altogether unless you cannot add exceptions to it.
Delete unnecessary folders. Open up "My Documents" and double-click "Battlefield 2." Delete the "dmp," "LogoCache" and "mods" folders.