Lately ive noticed more and more that my computer has been having trouble connecting to some filesharing clients, chat clients, and some online multiplayer games. I contacted comcast, my internet service provider, and asked if they connected me through a proxy or if i was behind a firewall. They answered me that no im not connected through a proxy, and that they have not placed be behind a firewall(nor do i have any software firewalls installed)...however tech support told me that my router my have a firewall built in.... Im using an RCA DCM235 cable modem, and i have no clue what i should do next, and i would really like to get this solved(if possible) any information is appreciated