Internet Loses Connection Constantly

I keep losing internet connection about every 5 minutes during the evening. It's almost like it resets itself and then comes right back for another 5 minutes. Gets very annoying after a while. I have the following modem:

Make and Model: DCI382R

It's something wrong with the internet or the modem as it happens with all of my devices (laptop, phone, iPad, etc.). Is there something I can try or do I need a new modem/router?