The problem is that packets (information) traveling across the vast array of Internet Hubs (Networks) are getting lost. That means information about the game such as bullets fired, hitting targets, plane locations, plane angles, etc... is being lost while traveling to and from your computer. Therefore you're lagging. All you can do is optimize your system in hopes of reducing the lag. However, in the end everything comes down to your ISP (Internet Service Provider) and how they route packets.
