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C7000-100NAS randomly drops internet connection
Hello, My C7000-100NAS modem seems to randomly drop it's Comcast connection. This happen on 2.4 ghz, 5 ghz, and wired connections. There is no pattern, however the dropped connection usually last...
I too had internet drop issues.
I had very similar power levels to the ones you posted. I see also that you have a ton of uncorrectable errors which was what I had also.
I focused my efforts on eliminating the uncorrectable errors. I read in other places that the ideal downstream power level is 0db and upstream should not be more than 50db. My levels were 4db to 6db downstream and 45db~46db upstream so I decided to try a 3db attenuator. Since I installed the 3db attenuator a few weeks ago I have not seen any unrecoverable errors. My downstream power levels are all below 3db now and my upstream levels are 47db~49db. I bought the 3db attenuator on Amazon for about $9. I will post here again if problems return. If you don't hear from me it means it is still working fine.
One other note, with so many uncorrectable errors you might have physical connection issues. Check all coax connections to make sure they are snug.
Well, I just found out my teenage boys have been reseting the modem on a regular basis.
So my fix was not a fix after all.
Back to debug mode!
It is often very difficult to determine if the modem-router is at fault (unstable, corrupted OS, etc.) or if the problem is caused by the ISP (throttled streaming, downgraded service, etc.). Thus, IT folks always suggest to "reset" the device, which often seems to correct the problem. In this case, the "reset" performs two functions. It clears any faults in the modem-router's operation, restoring all parameters; and reestablishes the ISP connection, restoring the identity and service subscription of the customer. And thus, download speeds and stable service are restored.
As in many cases, "engineering solutions" to such problems can be both "simple and effective". In this case, a universal solution to both potential causes would be to install a timer, which will shut off the modem-router and then it turn back on, automatically restoring/resetting modem-router performane and ISP subscription identity. For example, set the timer to turn off the modem-router at 3am, and restart at 4am, when no one requires internet access -- or some other convenient off-on setting (and "off time duration"). In some cases, the "timer reset" may be required several times during the day, again coordinated with need for internet access. This solution is elegant, simple and automatic. And, for those concerned about the ecosystem - it may save energy and reduce greenhouse gas emmissions.
The problem got worse after Comcast again came out and repaced the spliter again. Talking with Comcast they have now taken the C7000-1000NAS off the list of router/modem they would support. They came out and put in a new cisco router for free (no monthly charges) and we have not had one problem since. We now have a high price paper weight with the C7000-100NAS trying to sell it.
I don't know what happened but my internet has be pretty stable for months.
I have not had to reboot at all.
I took out the 3db attenuator that I had installed and then at some point things just got better on their own.
I have noticed that TWC is now bonding to ALL 24 channels on the modem for downstream.
That may have something to do with it.
Before it was only bonding on 16 channels.
It would be interesting to know how many channels are bonding on those with drop issues.
The maual is not very good in interpreting the chart and not sure that I am interpreting the screen correctly, but I think that there are 24 Downstream Channels and only 4 Upstream Bonded Channels.
Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 17 615000000 Hz 6 dBmV 40.1 dB 0 0 2 Locked QAM256 1 519000000 Hz 6.7 dBmV 40.7 dB 0 0 3 Locked QAM256 2 525000000 Hz 6.3 dBmV 40.5 dB 0 0 4 Locked QAM256 3 531000000 Hz 6.2 dBmV 40.5 dB 0 0 5 Locked QAM256 4 537000000 Hz 6.1 dBmV 40.5 dB 0 0 6 Locked QAM256 5 543000000 Hz 6.2 dBmV 40.6 dB 0 0 7 Locked QAM256 6 549000000 Hz 6.2 dBmV 40.5 dB 0 0 8 Locked QAM256 7 555000000 Hz 6.2 dBmV 40.5 dB 0 0 9 Locked QAM256 8 561000000 Hz 6.1 dBmV 40.4 dB 0 0 10 Locked QAM256 9 567000000 Hz 6 dBmV 40.4 dB 0 0 11 Locked QAM256 10 573000000 Hz 5.8 dBmV 40 dB 0 0 12 Locked QAM256 11 579000000 Hz 5.9 dBmV 40.2 dB 0 0 13 Locked QAM256 12 585000000 Hz 5.9 dBmV 40.4 dB 0 0 14 Locked QAM256 13 591000000 Hz 5.9 dBmV 40.3 dB 0 0 15 Locked QAM256 14 597000000 Hz 5.8 dBmV 40.3 dB 0 0 16 Locked QAM256 15 603000000 Hz 6 dBmV 40.3 dB 0 0 17 Locked QAM256 16 609000000 Hz 6.7 dBmV 41.4 dB 0 0 18 Locked QAM256 18 621000000 Hz 6.6 dBmV 41.3 dB 0 0 19 Locked QAM256 19 627000000 Hz 6.4 dBmV 41.4 dB 0 0 20 Locked QAM256 20 633000000 Hz 6.6 dBmV 41.4 dB 0 0 21 Locked QAM256 21 639000000 Hz 6.6 dBmV 41.4 dB 0 0 22 Locked QAM256 22 645000000 Hz 6.6 dBmV 41.4 dB 0 0 23 Locked QAM256 23 651000000 Hz 6.5 dBmV 41.4 dB 0 0 24 Locked QAM256 24 657000000 Hz 6.6 dBmV 41.4 dB 0 0 Upstream Bonded Channels Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 81 5120 Ksym/sec 36400000 Hz 43.5 dBmV 2 Locked ATDMA 82 5120 Ksym/sec 29500000 Hz 43.3 dBmV 3 Locked ATDMA 83 5120 Ksym/sec 22600000 Hz 42 dBmV 4 Locked ATDMA 84 5120 Ksym/sec 15700000 Hz 42.5 dBmV 5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV TWC-Spectrum service upgraded to 24 down / 4 up recently. Here is a good site to check your connection's performance: https://www.dslreports.com/speedtest.
From "SpeedGuide.Net" web site:
Downstream Power (-15dbmV to +15dbmV) - measure of the signal level received by the cable modem
Most modems are rated from -15dB to +15dB, however it's best to have it between +8dB and -8dB. Anything less or more than that and you may have quality issues. You can remove splitters on the line if you need to raise and clean up your signal level a bit. You can also use a tap (directional coupler) to get a cleaner signal to the cable modem instead of a splitter.
Upstream Power / Modulation(37dbmV to 55dbmV) - the strength of signal transmitted by the cable modem
Generally a lower this number is better. Above 55dB will most likely cause problems, over 57dB and you probably won't be able to connect. Ideally between 42 and 50dB. Lower than 40 may start introducing some packet loss (especially if you have much noise on the line). If you hit 58 the modem will likely drop the connection and resync.
Signal/Noise Ratio (SNR , >30dB) - measure of how clear the signal is
SNR is best over 30, (the higher the better, might work well with as low as 25 at times). Anything less than 25 will cause dropped connections, packet loss, slow transfers, etc. This is true for both the "Downstream SNR" and the "Upstream SNR", which may be different values. Typically, cable modems show the Downstream SNR, the Upsteram SNR can only be calculated at the remote end of the coax (usually at the node). Just remember that higher SNR means cleaner signal. A value well over 40 may mean you have too much power.
