My internet connection was running at about 3Mbps until round a month ago when it dropped to 1.5. I didnt think much of it until today when the internet periodically started dropping entirely for around 20 seconds at a time. When it comes back up, it is running at barely 700Kbps for 20-30 minutes before going back to 1.5Mbps. Modem shows a DC on the webpage but never turns off entirely. Modem is a westell 6100. any thoughts?