(Very) Slow Internet Speeds

For the last few days I have been having very slow internet, less than 3Mbps.

Here is the speed test: http://stage.results.speedtest.comcast.net/result/413101044.png

My modem is a TM502G/CT, and I have  tried to check my signal strength, but no matter what I do, I time out when trying to connect to 192.168.100.1