Comcast cable Internet randomly stops working. What can I do?

[Mark]

We have Comcast cable Internet at our apartment, using a coaxial input (that's all that the apartment has). The past couple months have been perfectly fine, but now at some point every afternoon, it will just randomly crash and stop working for about five to ten minutes. I know it's either the provider or the router because every device we use disconnects at the same time. I just don't know if it's a provider problem or a router problem, how to tell, and what I could possibly do to fix it.
It seems to only happen when we play DOTA 2 online. Maybe it's just coincidence, but it hasn't happened any other time. I just turned off IP Flood Detection on the router, I don't know if that would even help or not.