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Internet connection intermittently drops

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Internet connection intermittently drops

Hello,

 

I am experiencing issues with intermittent internet loss from my xfinity internet. This occurs for the wired and wireless connection. I have a Netgear cable modem router model 3700. I had a comcast tech come out today and he checked all the connections and told me everything was working fine. My internet connection will randomly drop for anywhere between 30s to 3-4 min about every hour or so. All of the lights on the router appear to show everything is functioning normally but cannot connect with any devices. 

 

I checked the router event log and am getting several critical events that keep occuring (see below). Any additional troubleshooting tips? Thanks! 

 

2018-8-25, 10:02:24 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 10:53:44 Warning (5) MDD message timeout;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 10:53:44 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 10:58:14 Warning (5) MDD message timeout;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 10:58:14 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:46:35 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:46:39 Warning (5) MDD message timeout;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:46:40 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:47:14 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:47:15 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:47:22 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:47:23 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:47:26 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:47:27 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:13 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:14 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:28 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:29 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:52 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:53 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:54 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:48:56 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:49:01 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:49:02 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:50:27 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:50:52 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2018-8-25, 11:58:45 Warning (5) MDD message timeout;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
2018-8-25, 11:58:45 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=6c:b0:ce:b8:fa:52;CMTS-MAC=00:01:5c:88:68:49;CM-QOS=1.1;CM-VER=3.0;
Expert

Re: Internet connection intermittently drops

Also post the signal stat figures.


Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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Official Employee

Re: Internet connection intermittently drops

Hello, jwatson310!

I would be more than happy to help you with this connectivity issue you are having. I do see your initial post was a few days ago and I know that we had a bit of planned maintenance in the area. Is your connection still dropping? 


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Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
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