The outage map for Comcast Corp. screamed red for downed and slow internet on Monday afternoon.

Comcast, the nation's largest residential internet provider, acknowledged the dodgy internet and pointed to connection issues with telecom backbone provider Level 3. Level 3 said it fixed the problem.

Comcast subscribers in Denver, Portland, San Francisco, Houston, Minneapolis, and Boston reported the slowest speeds and most outages. A Reading man said on that his internet had been slow in the afternoon but speeds had improved.

Comcast said on Twitter at 1:36 a.m. on Monday that "some customers are having issues their Xfinity internet service."

At 5:34 p.m., Comcast tweeted that its service was restored.