This is the wrong section, and I believe you mean to say ping? Well first I think you should try getting better Internet or closing any other program that might be using internet while you are playing crossfire.
Close any programs that you don't need.
Don't download anything while playing crossfire.
Try getting game booster or pando media booster and see if any of those help, I don't know if they do =\ I heard gamebooster is good though.