Reset modem through node red

General
21

If you are getting odd noise when you talk on a call, that is an upstream issue, if people say you are breaking up, choppy for example. If you hear breaking up of voices, or choppy, that is a downstream issue. Make sure you don't here any breaking of audio (up or down) when NO ONE else is using your bandwidth, that will define your baseline is ok. If you get bad quality when no one else is using your bandwidth, that means either your ISP is limiting something or you are sending and receiving a lot of bad data or modem maybe retrying to get good data.

You should have power between 10/-10, which is ok for most modems. For your make and modem of modem there should be a specification sheet on what is normal ranges, and your ISP should publish the same as well.

As for your ping returns say to www.google.com being both faster and slower, that could be from a number of scenarios. Need more data to know if that is an issue or not. Each route of a ping can vary greatly based on what others are doing at the time you do the ping test. Cable is a SHARED bus, so if others are streaming a lot, you would expect your pings to be slow, etc.

Do you have any view that shows the correctable and uncorrectable codeword errors? This is also a good metric for tracking issues.

Here is a snapshot of my cable modem...

Downstream 	Bonding Channel Value
Channel ID 	15  	16  	17  	18  	19  	20  	21  	22 
Frequency 	663000000 Hz 	669000000 Hz 	675000000 Hz 	681000000 Hz 	687000000 Hz 	693000000 Hz 	699000000 Hz 	705000000 Hz 
Signal to Noise Ratio 	36 dB 	36 dB 	36 dB 	36 dB 	37 dB 	36 dB 	36 dB 	36 dB 
Downstream Modulation 	QAM256 	QAM256 	QAM256 	QAM256 	QAM256 	QAM256 	QAM256 	QAM256 
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
	-9 dBmV  	-9 dBmV  	-9 dBmV  	-9 dBmV  	-9 dBmV  	-9 dBmV  	-10 dBmV  	-10 dBmV  

Upstream 	Bonding Channel Value
Channel ID 	17  	20  	19  	18 
Frequency 	17800000 Hz 	37000000 Hz 	30600000 Hz 	24200000 Hz 
Ranging Service ID 	9281 	9281 	9281 	9281 
Symbol Rate 	5.120 Msym/sec 	5.120 Msym/sec 	5.120 Msym/sec 	5.120 Msym/sec 
Power Level 	44 dBmV 	47 dBmV 	46 dBmV 	45 dBmV 
Upstream Modulation 	[3] QPSK
[1] 16QAM
[2] 64QAM
 	[3] QPSK
[1] 16QAM
[2] 64QAM
 	[3] QPSK
[1] 16QAM
[2] 64QAM
 	[3] QPSK
[1] 16QAM
[2] 64QAM
 
Ranging Status 	Success 	Success 	Success 	Success 

Signal Stats (Codewords) 	Bonding Channel Value
Channel ID 	15  	16  	17  	18  	19  	20  	21  	22 
Total Unerrored Codewords 	3782278605 	3782294806 	3782259374 	3782317826 	3782261177 	3782258912 	3782254714 	3782258905 
Total Correctable Codewords 	8780 	9058 	10931 	4134 	687 	3032 	9960 	4669 
Total Uncorrectable Codewords 	1661 	2428 	1458 	1527 	2111 	1658 	620 	2687

Here is the datasheet for my modem...
https://arris.secure.force.com/consumers/articles/General_FAQs/SB6141-Cable-Signal-Level/?l=en_US&fs=RelatedArticle#:~:text=Acceptable%20SNR%20Levels%20(dB)%3A,be%2033%20dB%20or%20greater.

Notice my downstream SNR is below 39, the higher the better is the general rule, but it varies based on the QAM settings, so I have good quality signals coming my AMP, and I have a signal filter on the AMP, so that helps keep the SNR up even though by cable modem is a long distance from my AMP and the ISP hub. But too high is also an issue, which most tutorials do not explain as an issue. But lets ignore that for now.

My upstream SNR is a bit off specification, but again, I have a long distance between point to point as noted above. As long as I am just gaming and surfing, I am not sending a lot of data back to the ISP compared to a business or such, so I am not flooding the up channels. Thus a bit more noise, or lower ratio is ok. If either my downstream or upstream signals degrade, I will see the correctable and uncorrectable errors start adding up faster than in the past. As you can (not) see my error counts are low and stay low... no spiking.

22

If you can see the codeword counts and the modem logs, to watch the number of line resets, then you can develop over time a good baseline and have NR report anything that varies against the baseline. This is what I do as well. The second I see an increase of resets (and the ISP is not pushing firmware updates or such) or the number of uncorrectable codewords spikes, I have reason to talk to my ISP. Of course if the SNR goes above 40 for downstream and above 45 for upstream in my case as well I talk to my ISP.

23

Oh, I should have said this before, if anything is out of range for power levels and you have a dedicated AMP, your ISP should be able to adjust accordingly. This should improve both the stability and performance of your internet experience. Even if you have a shared AMP, say in apartment building, there is still some adjustments that the ISP can do to improve things if your SNRs are out of acceptable ranges, it just depend on how many lines you have and how many devices you have on each line.

24

Thanks, I only know how to access the web interface of the modem, I am not sure if there are other way. What I can see is what I shared. I can also see system log but seem short and some detail is cut out from the web interface. I will try to find out if there a (hidden) way to extend the info on the web interface
One thing I wanted to point out:

  1. My house is relatively new in a relatively new residential suburb area (built 2014). I would hope this eliminates certain potential issues related to old infrastructure
  2. My ISP is a small one that buys wholesales bandwidth from one of the large ISPs

Does this make a difference? Would the discussion with my ISP change (i.e. they may have limited capacity to address an issue?)

System Log

Time Priority Description
Tue Sep 15 08:55:07 2020 Warning (5) DHCP WARNING - Non-critical field invalid in response ;CM-MAC=BLURRED!;CMTS-MAC=BLURRED2!;CM-QOS=1.1;CM-VER=...
Tue Sep 15 08:55:12 2020 Notice (6) Honoring MDD; IP provisioning mode = IPv4
Tue Sep 15 08:55:01 2020 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=BLURRED!;CMTS-MAC=BLURRED2!;CM-QOS=1.0;CM-VER=3.0;
Tue Sep 15 08:54:50 2020 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c4...
Tue Sep 15 08:54:17 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=BLURRED!;CMTS-MAC=BLURRED2!;...
Time Not Established Warning (5) DHCP WARNING - Non-critical field invalid in response ;CM-MAC=BLURRED!;CMTS-MAC=BLURRED2!;CM-QOS=1.0;CM-VER=...
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv4
Sat Sep 12 21:58:05 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=BLURRED!;CMTS-MAC=BLURRED2!;...
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=BLURRED!;CMTS-MAC=BLURRED2!;CM-QOS=1.0;CM-VER=3.0;
25

Your log, is pretty much a typical log, ISPs often send control codes/messages, and your modem often reacquire its ip unless you have a static ip, which typically is only done if you host a server or have a business account. You can always request a static ip for extra $$$ with most ISPs.

The log information you showed here, does not show a reset or reboot, which is good, you don't want resets or reboots that are not scheduled, or expected.

Infrastructure issues can happen at anytime, typically water damage is common on the truck lines between your local hub and your house being typically underground. I have had to have my trunk line replaced very few years, even through I live out in the desert, the problem out here is heat, wires have memory, meaning they don't like to be flexed, or move once set in place, every time a trunk line is moved, pushed, etc. say when new lines are pulled or added to the same conduit, it can impact the quality of the physical cable you are using.

Now if you can find in your model setup, where the codeword statistics are, we would have the full picture of what you have to work with. A lot of uncorrectable and/or correctable codewords, adding up over a short period of time is an indicator of several possible issues.

Your ISP is just a VAR (value added reseller), so all technical support comes from the parent ISP right?

26

My ISP (Carrytel) is not a pure reseller. Below describe their technical model even though is for a different ISP.
In my case, my house came wired by Rogers (a large player) and I got their service for a year. With carrytel, I believe they "reuse" (pay?) to use the last mile getting to my home. Carrytel then connect to their backbone infrastructure and to the internet.
TekSavvy Solutions Inc. is a Canadian residential, business, and wholesale telecommunications company based in Chatham, Ontario. In most of the country, it is a wholesale-network-access-based service provider and voice reseller, connecting its service to existing last mile networks from telecom carriers Bell Canada (including Bell Aliant) and Telus Communications, and cable carriers Rogers Communications, Cogeco Cable, Shaw and VidƩotron. However, in parts of rural southwestern Ontario, the service is provided over TekSavvy's own fixed wireless network (branded as "Sky Fi").

27

Sadly, based on a quick research sounds like my modem doesnt log codewords...
https://www.amazon.com/review/R1G0O8LGRWNOS8/ref=cm_cr_srp_d_rdp_perm

28

That is really a shame. You might want to consider replacing it if possible to get such data. It really is key to finding and resolving some of the common issues.

29

Thanks, not sure if I will be replacing the modem any time soon. I purchased it around 18 months ago and only used 6 months (other ISP didn't let me bring my modem)
Today, I had a terrible ping time to google 20ms - 700ms
With regards to how to temporary correct the problem (through intervention on my local equipment)
I can confirm that power cycle the ROUTER did not make a different
A reboot (through menu) of the MODEM brought the ping to 13-18ms which is expected / good for me

30

Reboot of the cable modem does several things, first, it forces the channels to reinitialize, so if you are lucky you get channels that are open/least used. Reboot of the cable modem also forces a DHCP release and request (unless you have a static IP assignment), this alone is not a big deal, but it does kill any existing session traffic. So you ping maybe faster, ONLY because you ping before all other traffic is coming and going again.

Do you have anyone else in the home streaming or using internet access? Remember your router and cable modem are a shared device with limited resources.

Just an idea, but when you run a speed test, is the test results consistent or faster or slower at different times of the day? Cable (COAX) is bus network design, so any other customer on the same trunk line as you, is sharing available bandwidth.

I wrote a python script, and am converting it to an NR flow that does a speed check about every 15 minutes, and if I get a result that is out of the acceptable range, I get an email alert.

31

Thanks
My external IP address never changes even though I am not paying for that. As for ping, it is not really correlated to other traffic inside my home. Several times, I run into the issue early in the morning when I am the only person up and not doing anything crazy. After reset connection improves significantly and pings get very close 13-15ms (before is between 30-300ms)
Speed test work fine regardless the time of day. It is not really a speed issue. Also have a family that happily watches netflix/youtube at other times without a problem.
Problem mostly small video/voice artifacts during live calls.
In the end:

  1. I realized I have to do this most days
  2. I don't seem to have a reliable way to detect programatically bad quality
  3. It seem a little involved to programatically reset the modem (simulate mouse click). I am busy at work at this requires a larger effort than I anticipated (and outside my expertise)

Since it looks it is not bad to do this every day I have setup a smartthings+zigbee switch automation to reset the modem at 4am (PS. it took a couple of tries to get it to work all locally - without internet)

Depending how it goes also, I may buy the modem TC4400 that shows uncorrectable codewords and is compatible with local ISPs. (I read somewhere that ISP may remotely disable codewords screen... hopefully not).

REALLY, appreciate all your comments about ISP and modem logs.

32

Well, glad to help as I could. I still would encourage you to push your ISP to solve the issue, IMHO, this would be best.

My setup, I have a 30 second delay circuit, between power down and power up events. So as long as I have an authenticated power down via my smart plug, the power up is guaranteed. Sneaky but works. But like you, I had to find a way to avoid external authentication. Smart plugs that have a count down timer, make this scenario easy to do. :slight_smile:

As for the streaming, NetFlix, etc. The nature of the transport protocol for video playback does (usually) sufficient buffering that modem temporary drop outs may never be noticed. For example, when I am streaming from various services like NetFlix, I can power down my router/modem for several minutes, and video playback is fine. This is by design to provide consistent viewing experience because the actual transport via the internet is highly random in performance end to end.

33

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