Having lots of ping drops in 95132

Hello LMeng, thank you for taking the time out of your busy day to get this issue addressed. I know in this day and time we depend on internet for so many things it's imperative that the service works at all times. You've certainly come to the right place to get your issue repaired, we specialize in everything Xfinity and our Digital Care team is the absolute best when it comes to troubleshooting at your convenience. To get the ball rolling on this could you please send me a private message by following the steps below? 

To send a "Peer to peer" ("Private") message:
Click "Sign In" if necessary
• Click the "Peer to peer chat" icon
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line
• Type your message in the text area near the bottom of the window
• Press Enter to send it

FWIW, DNS servers may not be a good target for pinging as some of them are deliberately configured to rate limit / de-prioritize ICMP packet based ping probes. So you'll see lots of timeouts there. Try pinging www.google.com instead.

Is this with a WiFi connection ? If so, for a test, does a computer that is hardwired directly to the router / gateway device with an ethernet cable have the same problem ?

With this test, we are trying to isolate this from being either a WiFi-only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good first step of troubleshooting before proceeding any further. 

The issue has been fixed after ~36 hours.

I have no detail what Comcast did. My Internet was down for ~2 hours then everything came back up without any issue.