Xbox connection fluctuating?

For the past 2 hours my connection on my xbox has been fluctuating quite a bit. Every 10-15 seconds I would go down to a red bar then after about 5 seconds it would come back up to a green bar. The only thing I can think to do now is to lower my MTU, but how much? Automatically it is at 1500, what should I lower it to if it will even help. Any other suggestions on what I could do?