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Internet connection constantly dropping

New Poster

Internet connection constantly dropping

Our internet is dropping anywhere from 1 to ~10 times an hour.  Its been happening for several months now on all devices in the house either wired or on wifi.

Initially i was using my own modem (SB6190) but am now using the Xfinity provided modem.  Im not sure of the model but its the latest DOCSIS 3.0 modem from Scientific Atlanta.  Regardless of the modem, the issues still occurs.  The rate of connection drops seems to increase in peak hours (evenings and weekends)

 

Xfinity techs have come to our home twice to check on the issue and in both instances could not find a problem.   They told us if they don't see an issue while they are present there isn't anything they can do.  im not sure how to proceed so if anyone has any ideas or suggestions i would love to hear them.

 

Thanks.

Connection Expert

Re: Internet connection constantly dropping

Start here;

 

http://forums.xfinity.com/t5/Your-Home-Network/Connection-Troubleshooting-Tips/m-p/1253575#U1253575




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Connection Expert
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Re: Internet connection constantly dropping

New Poster

Re: Internet connection constantly dropping

Speed tests are good when the connection is active: 235Mbps / 12Mbps / 12ms 

When the connection is dropped the tests obviosly won't run.

IPv6 tests passed.

IPv4 lease time is 3 days 12 hours

IPv6 lease time is 49710 days 6 hours.

 

 

 

Connection Expert

Re: Internet connection constantly dropping

The stats as read at the modem level at that moment in time were o/k but there are three additional signal stats which can't be read by the modem. They can only be read from their end by them polling the CMTS (Cable Modem Termination System) at the local headend facility.

They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.

You can call in and ask what these figures are. The Upstream Receive Power Level should fall within the range of -2dB to +2dB with 0dB being in the middle and perfect.

The Upstream SNR should be least 31dB, and the higher it is the better.

The ICFR should be no higher than 2 dB.

You could have an intermittent noise ingress issue in only the upstream channel(s) / return path only somewhere.

They will be able to see whether or not everything is in the green zone and also see a history plot for the modem.





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New Poster

Re: Internet connection constantly dropping

The numbers are good

Upstream Rx Power – 0.0dB

Upstream SNR – 34.3dB

Upstream ICFR – 1.82dB

Connection Expert

Re: Internet connection constantly dropping

Yep. But obviously you have something intermittent going on there. FWIW, there are some known issues / quirks with the current firmware version for that modem. Hopefully Arris and CC will get them straightened out and CC will push an updated version with the needed fixes. Good luck !




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