Intermittent disconnects

Need Help?

That's what we're here for! The goal of the Rogers Community is to help you find answers on everything Rogers. Can't find what you're looking for? Just ask!
cancel
Showing results for 
Search instead for 
Did you mean: 
Reply
Highlighted
Resident Expert
Resident Expert
Posts: 6,985

Re: Intermittent disconnects

@MANUNITEDONE call tech support and ask the customer service rep to run a signal check on the modem.  It should fail automatically as you don't have a DOCSIS 3.1 OFDM channel running and you only have one DOCSIS 3.0 upstream channel running instead of three or four channels.  You can let the CSR know that your OFDM channel is dead and that you only have one upstream channel running.  

 

When the test is complete, the CSR should arrange a tech visit at your convenience.  

 

When the field tech has completed his or her work, can you post the signal levels again to ensure that the tech visit has resulted in the correct channels running on the modem. 

 

Just to note the signal channel will result in slow downstream and upstream operation.  Your signal levels are a little unusual as the downstream channels are usually worse than what is shown, given the upstream signal level.  That upstream level should be in the 36 to 40 dBmV range instead of operating at 49 dBmV or higher.  



Highlighted
I'm Here A Lot
Posts: 7

Re: Intermittent disconnects

Thank you, we'll do and post again.
Highlighted
I've Been Here Awhile
Posts: 3

Re: Intermittent disconnects

Hi, I am experiencing frequent intermittent disconnects.  Usually lasting around 10 seconds at a time.  Had one day with an outage of a few hours.  A ticket was opened for that event.  Internet is working again, but the frequent intermittent disconnects are still occurring.

 

Can someone please interpret this table? Thank you in advance

 

CODA-4582U Modem

 

Downstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDSignal noise ratio (dB)
1597000000256QAM-13.900834.346
2849000000256QAM-22.000227.607
3855000000256QAM-21.500327.579
454300000064QAM-26.90044.191
5579000000256QAM-12.900534.926
6585000000256QAM-13.400634.926
7591000000256QAM-13.100734.926
8279000000256QAM-11.200137.356
9603000000256QAM-14.600934.484
10609000000256QAM-14.3001034.484
11615000000256QAM-15.1001133.834
12621000000256QAM-14.7001233.957
13633000000256QAM-15.2001333.487
14639000000256QAM-15.1001433.487
15645000000256QAM-15.5001533.377
16651000000256QAM-14.8001633.834
17657000000256QAM-14.5001733.957
18663000000256QAM-14.2001834.346
19669000000256QAM-14.3001933.957
20675000000256QAM-14.9002033.377
21681000000256QAM-15.3002133.377
22687000000256QAM-15.5002233.063
23693000000256QAM-14.7002333.487
24699000000256QAM-14.7002433.487
25705000000256QAM-14.7002533.957
26711000000256QAM-15.2002633.377
27717000000256QAM-15.2002733.487
28723000000256QAM-15.2002833.063
29825000000256QAM-20.9002928.642
30831000000256QAM-21.8003027.967
31837000000256QAM-22.0003127.724
32843000000256QAM-22.6003227.170
OFDM Downstream Overview
ReceiverFFT typeSubcarr 0 Frequency(MHz)PLC lockedNCP lockedMDC1 lockedPLC power(dBmv)
0NANANONONONA
14K275600000YESYESYES-14.799999
Upstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDBandwidth
130596000ATDMA - 64QAM48.75016400000
238596000ATDMA - 64QAM50.25033200000
323700000ATDMA - 64QAM41.50026400000
OFDM/OFDMA Overview
Channel IndexStatelin Digital AttDigital AttBW (sc's*fft)Report PowerReport Power1_6FFT Size
0DISABLED0.50000.00000.0000-inf-1.00004K
1DISABLED0.50000.00000.0000-inf-1.00004K
Highlighted
Resident Expert
Resident Expert
Posts: 6,985

Re: Intermittent disconnects

@dancira  you have external cable and/or connector problems.  The signal range for DOCSIS modems on the downstream side is +/- 15 dBmV.  You have signal levels below -15 dBmV, so their below the spec’d value.  The downstream signal to noise ratios should be in the 36 to 40 dBmV range, with your’s showing below the typical minimum of 36 dB.  So, low signal levels combined with electrical noise on the cable.  That’s not a good combination. 

 

The OFDM Downstream data doesn’t show enough data to determine the health of the OFDM channel, but, the PLC power level sitting at -14.8 dBmV isn’t good.  I’m surprised that the modem is actually still using the OFDM channel for its downstream data. I suspect that your downstream data rates aren’t where they should be.

 

The upstream data channels show 2 channels that are approaching the maximum modem output level of 51 dB.  Rogers uses 52 dBmV for some reason.  When that max output point is reached the modem starts to drop upstream channels, one by one, pushing up the power on the remaining channels in order to maintain comms with the cable system.  When that happens your data rates will drop.

 

As the external cable system and its connectors age, the normal signal loss thru the cable will increase.  The cable is subjected to weathering that usually results in water ingress into the cable, shorting out the cable and causing signal loss such as what you are seeing.  That happens whether the cable arrives via underground path from a local pedestal, or overhead from the nearest utility pole.  So, when the cable reaches a failure point a tech visit is required to inspect and possibly replace the cable and its connectors.

 

Was the ticket opened for a tech visit? 



Highlighted
I've Been Here Awhile
Posts: 3

Re: Intermittent disconnects

Thank you @Datalink.  

 

I will follow-up on my ticket and request a tech visit.  I am guessing the ticket was only addressing the outage. 

Highlighted
Resident Expert
Resident Expert
Posts: 6,985

Re: Intermittent disconnects

@dancira call tech support, advise the tech of the pre-existing ticket and ask him or her to run a signal check on the modem.  That check should fail automatically.  At that point, the tech should look at the existing ticket, and the failed test results and setup a tech visit time for you.  There should have been a tech visit arranged during the previous call. 



Highlighted
I've Been Here Awhile
Posts: 3

Re: Intermittent disconnects

Thanks @Datalink.  I chatted with tech support.  From their end they could see the high noise, and signal issues, with high packet loss.  I was informed that issue could have been related to the outage that was still open from previous ticket.  They escalated a new ticket based on the intermittent disconnects issue.  I was told I will receive an update within 48 hours.  

 

I have not received an update - but it seems that my intermittent issues have now been resolved.  Hopefully I am not jinxing it.  Signal/noise data still might not be optimal.

 

Downstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDSignal noise ratio (dB)
1597000000256QAM-14.300833.957
2849000000256QAM-22.500227.249
3855000000256QAM-22.200327.042
454300000064QAM-27.50044.191
5579000000256QAM-13.500534.484
6585000000256QAM-14.100634.212
7591000000256QAM-13.800734.484
8279000000256QAM-10.000137.636
9603000000256QAM-14.900934.346
10609000000256QAM-14.5001034.346
11615000000256QAM-15.4001133.487
12621000000256QAM-15.1001233.957
13633000000256QAM-15.5001333.377
14639000000256QAM-15.3001433.377
15645000000256QAM-15.7001533.063
16651000000256QAM-15.1001633.487
17657000000256QAM-14.9001733.834
18663000000256QAM-14.7001833.834
19669000000256QAM-14.9001933.487
20675000000256QAM-15.6002033.063
21681000000256QAM-15.7002133.063
22687000000256QAM-15.8002232.963
23693000000256QAM-15.0002333.487
24699000000256QAM-15.0002433.377
25705000000256QAM-15.1002533.487
26711000000256QAM-15.7002633.063
27717000000256QAM-15.6002733.063
28723000000256QAM-15.8002832.676
29825000000256QAM-21.7002927.967
30831000000256QAM-22.4003027.438
31837000000256QAM-22.4003127.383
32843000000256QAM-23.0003226.869
OFDM Downstream Overview
ReceiverFFT typeSubcarr 0 Frequency(MHz)PLC lockedNCP lockedMDC1 lockedPLC power(dBmv)
0NANANONONONA
14K275600000YESYESYES-13.599998
Upstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDBandwidth
130596000ATDMA - 64QAM49.00016400000
238596000ATDMA - 64QAM50.25033200000
323700000ATDMA - 64QAM42.50026400000
OFDM/OFDMA Overview
Channel IndexStatelin Digital AttDigital AttBW (sc's*fft)Report PowerReport Power1_6FFT Size
0DISABLED0.50000.00000.0000-inf-1.00004K
1DISABLED0.50000.00000.0000-inf-1.00004K

 

Highlighted
Resident Expert
Resident Expert
Posts: 6,985

Re: Intermittent disconnects

@dancira at this point, looking at your signal levels, you're no further ahead.  The downstream signal levels are still well below acceptable levels.  Looking at the upper DOCSIS 3.0 signal levels, I'm surprised that the modem is still running the DOCSIS 3.1 OFDM channel.  I have no doubt that you're seeing terrible downstream performance. 

 

The upstream levels have problems of their own.  One channel is close to failure, followed by a second channel not too far behind it.  Those channels, on their own wouldn't cause a signal check failure, but, when you look at the downstream signal levels and these upstream levels its pretty clear that there is a serious problem on the go. 

 

If tech support is refusing to arrange for a tech visit, the only reasonable reason for that is that your immediate neighbours have the same problem and potentially the neighbours down and up the street as well.  In that case, ok, thats more of an area problem that requires a maintenance crew to fix.  If you're on your own, in terms of the signal levels, then you have an external cable problem from your home to the nearest pedestal or utility pole, depending on which cable feed you have, either underground or overhead.  

 

If tech support isn't calling you, call them.  If tech support is indicating that a ticket is in progress or has been raised to resolve your signal problems, ask for that ticket number so that you can call back, every day, to determine the progress of that ticket.  

 

You should be taking a look at those signal levels on a daily basis to see if they are improving at all.  The downstream channels should look as follows all the way to the bottom port 32.

 

Downstream Overview

Port ID Frequency (MHz) Modulation Signal strength (dBmV) Channel ID Signal noise ratio (dB)
1 597000000 256QAM 0.0  8 36 to 40 

 

The remaining downstream DOCSIS 3.0 channels should look the same, in terms of QAM number, signal level and signal to noise ratio.

 

OFDM Downstream Overview

Receiver FFT type Subcarr 0 Frequency(MHz) PLC locked NCP locked MDC1 locked PLC power(dBmv)
0 NA NA NO NO NO NA
1 4K 275600000 YES YES YES 0.0

 

The PLC power level should be close to 0 dBmV or possibly slightly positive.

 

Upstream Overview

Port ID Frequency (MHz) Modulation Signal strength (dBmV) Channel ID Bandwidth
1 30596000 ATDMA - 64QAM usually 30 to 32/33 1 6400000
2 38596000 ATDMA - 64QAM usually 30 to 32/33 3 3200000
3 23700000 ATDMA - 64QAM usually 30 to 32/33 2 6400000

 

With the modem running DOCSIS 3.1 on the downstream side, it usually runs the upstream DOCSIS 3.0 channels in a 30 to 32/33 dBmV range.  The maximum range for the upstream transmit power level is 51 dBmV according to the DOCSIS specs and Rogers uses 52 dBmV as a failure point.  By that point I expect the modem to shutting down at least one channel in order to transmit enough power in the remaining channels to allow the modem to communicate with the upstream cable network.  

 

So, bottom line, on its own, your external cable system is in terrible shape and without any change, you can expect the upstream channels to start shutting down, one by one.  You will know when that happens as your data rates will decrease even more.  You need to press tech support for an answer on how far the signal level problem extends, is this a one of, as in your external cable feed, or is this a wider problem, and you should be checking every day to determine what progress has been made, or not 😞



Highlighted
I've Been Around
Posts: 1

Re: Intermittent disconnects

Hi

 

I'm having the same issue.  Can anyone help?

 

Downstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDSignal noise ratio (dB)
1603000000256QAM2.100938.983
2579000000256QAM2.300538.983
3585000000256QAM1.900638.983
4591000000256QAM1.900738.605
5597000000256QAM2.000838.983
6279000000256QAM0.300137.636
7609000000256QAM2.4001038.983
8615000000256QAM2.3001138.983
9621000000256QAM2.6001238.983
10633000000256QAM2.4001338.983
11639000000256QAM2.4001438.983
12645000000256QAM2.1001538.605
13651000000256QAM2.1001638.605
14657000000256QAM1.7001738.605
15663000000256QAM1.8001838.605
16669000000256QAM1.5001938.983
17675000000256QAM1.5002038.605
18681000000256QAM1.6002138.605
19687000000256QAM1.5002238.983
20693000000256QAM1.7002338.605
21699000000256QAM1.7002438.605
22705000000256QAM2.1002538.605
23711000000256QAM2.3002638.605
24717000000256QAM2.5002738.605
Upstream Overview
Port IDFrequency (MHz)ModulationSignal strength (dBmV)Channel IDBandwidth
123700000ATDMA - 64QAM41.75066400000
236996000ATDMA - 64QAM41.50086400000
313696000ATDMA - 64QAM41.00056400000
430596000ATDMA - 64QAM40.75076400000
Highlighted
Resident Expert
Resident Expert
Posts: 6,985

Re: Intermittent disconnects

@alllllll are you still having problems with your internet service?  Looks like I missed your post from Friday.  Can you log into the modem navigate to the STATUS .... DOCSIS WAN tab and copy the Downstream OFDM section and paste that into a post.  That will tell me what mode the modem is operating in for the downstream data, DOCSIS 3.0 using the upper DOCSIS 3.0 channels (1 to 32) or DOCSIS 3.1 using one single OFDM channel.