Multiplayer issues with BF3

I wasnt sure to post this under the BF3 thread already created, but this is more a tech issue then a game playing issue.

Ok I have been having this problem since I bought BF3 again over the holidays that included the game and the premium pack all in 1 for $40 bucks, a good deal for sure.

But since I started playing again on multiplayer, when I am in the game for 30min or more my connection will drop and actually reset my cable modem and give me a lost connection message.

This does not happen in BLOPS 2 or Halo 4 Multiplayer with hours of gaming.

I have searched google and found a couple things, made a couple changes in my router, but no go.

I currently rent a cable modem, I usually own my own, but I might buy a Motorolla cable modem to see if that will fix the issue.

My current cable Modem from Knology is a Arris docsis 3.0.

If anyone out there has any suggestions to fix this issue I would greatly appreciate your help.

Thanks!