Community Forum

Intermittent connection drops

Regular Contributor

Intermittent connection drops

We are at the end of a long run and have had intermittent connection issues since our service was installed in 2005. Right now we are having internet drop 1-3 times a day. Voice service never goes out, and TV X1 is laggy at times, but I hear that's the case from our neighbors too so I'm not sure if that is signal related.

 

 

  • Post your modem’s error logs. This information can usually be accessed by typing http://192.168.100.1 into your browser.

Error logs are mostly T3 timeouts:

Time Priority Description
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=60:e3:27:88:0a:58;CMTS-MAC=00:01:5c:74:a8:4b;CM-QOS=1.0;CM-VER=3.0;
Mon Apr 30 20:32:59 2018 Critical (3) Resetting the cable modem due to docsDevResetNow
Mon Apr 30 20:14:27 2018 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=60:e3:27:88:0a:58;CMTS-MAC=00:01:5c:74:a8:4b;CM-QOS=1.0;CM-VER=3.0;
Sat Apr 28 10:15:57 2018 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=60:e3:27:88:0a:58;CMTS-MAC=00:01:5c:74:a8:4b;...
Sat Apr 28 09:55:13 2018 Critical (3) Resetting the cable modem due to docsDevResetNow
  • Post the make and model of your modem.
  • TP Link CR700 running old firmware that Comcast hasn't updated in 2 years: Firmware Version: v1.1.0 Build 20160812 Rel515810 Hardware Version: V1.1
  • Post the make and model of your router if you have one.

Above is a combo modem / router

  • Let us know if you contacted Comcast or had a tech visit.

One came out a couple of weeks ago and spent about 2 hours going over all the connectors and replacing some of them.

  • Let us know what the lights on your modem are doing when you are having problems.

The lights stay on, no reboot until I manually reboot.

Another tech is coming Saturday. When I called last night they said downstream power was a problem, and I do see it's out of spec on some of the lower channels as I type this... thanks for any and all help.

Downstream Bonded Channels


Channel Status Modulation Channel ID Frequency Power SNR
1 Locked QAM256 10 525000000 Hz 10.2 dBmV 42.5 dB
2 Locked QAM256 11 531000000 Hz 10.0 dBmV 42.3 dB
3 Locked QAM256 12 537000000 Hz 10.1 dBmV 42.5 dB
4 Locked QAM256 13 543000000 Hz 9.9 dBmV 42.4 dB
5 Locked QAM256 14 549000000 Hz 9.9 dBmV 42.5 dB
6 Locked QAM256 15 555000000 Hz 9.7 dBmV 42.2 dB
7 Locked QAM256 16 561000000 Hz 9.4 dBmV 42.0 dB
8 Locked QAM256 17 567000000 Hz 9.2 dBmV 41.9 dB
9 Locked QAM256 18 573000000 Hz 9.2 dBmV 41.9 dB
10 Locked QAM256 19 579000000 Hz 9.5 dBmV 42.3 dB
11 Locked QAM256 20 585000000 Hz 9.3 dBmV 42.1 dB
12 Locked QAM256 21 591000000 Hz 9.0 dBmV 41.9 dB
13 Locked QAM256 22 597000000 Hz 8.7 dBmV 41.5 dB
14 Locked QAM256 23 603000000 Hz 8.7 dBmV 41.6 dB
15 Locked QAM256 24 609000000 Hz 9.0 dBmV 41.8 dB
16 Locked QAM256 25 615000000 Hz 9.0 dBmV 41.9 dB

Upstream Bonded Channels

 

Channel Status Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 23 5120 ksym/sec 30300000 Hz 40.8 dBmV
2 Locked ATDMA 21 5120 ksym/sec 17300000 Hz 44.0 dBmV
3 Locked ATDMA 22 5120 ksym/sec 23700000 Hz 41.8 dBmV
4 Locked ATDMA 24 5120 ksym/sec 36700000 Hz 39.5 dBmV
Expert

Re: Intermittent connection drops

Your signal levels look fine, but the modem can only give us limited information. So...

 

I've asked an employee to check the CMTS for real-time and historical RF signal reports from your modem. They can also check your local node/plant for any degradation or error reports. You can expect a reply in this thread. 


I am not a Comcast employee, just a moderator. Pls observe Wheaton's Law.
Regular Contributor

Re: Intermittent connection drops

Thanks, but I thought spec for downstream was -10 to +10... and how would a tech check without having my account info?

Expert

Re: Intermittent connection drops


@SFGold wrote:

Thanks, but I thought spec for downstream was -10 to +10

 

You're correct, but a little variation isn't really a concern.  Modems are typicaly +/- a few dB off in their reporting anyhow. 

 

... and how would a tech check without having my account info?

 

The specialist will ask for your account info via private message. They can see historical data for your modem as well as checking to see if something is happening in your neighborhood. 

 



I am not a Comcast employee, just a moderator. Pls observe Wheaton's Law.
Regular Contributor

Re: Intermittent connection drops

Awesome thanks.

 

In the meantime I have ordered a new modem (Netgear AC1900) wondering if a more powerful modem with more channels might help connection stability?

Official Employee

Re: Intermittent connection drops

Hi SFGold, I have responded to your private message.

 

Thank you

Official Employee

Re: Intermittent connection drops

Hi SFGold, thank you for working with me through private message and glad to hear everything is working after this last tech visit. Please reach back out if you have any questions in the future.

 

Thank you