internet outages

Recently there have been outages at random times for varying lengths. Resetting the modem doesn't work. It started several days ago over the Memorial Day weekend. Today it's fine. I'm wondering if there was a bandwidth shortage due to heavy use over the holiday. The modem is an Arrris Surfboard. The third blue light from the top doesn't light up. I checked Arris and no problems were indicated.

Thanks for your help.