Internet Keeps Dropping

[dlee1919]

Hi there,

I have the white CODA-4582 modem.

[Datalink]

Hi, ok, can you log into the modem and:

1. Check the Software (firmware) version listed on the Status page.  That page is displayed automatically when you log into the modem.  The version will either be 2.0.10.36T6 or possibly 7.1.1.30 which is very new and about to be replaced.  Please let me know which version is loaded.

2.  Navigate to the DOCSIS WAN tab and copy the signal table, starting with the Downstream Overview line and going to the very bottom of the table, the OFDM/OFDMA Overview section.  Select or highlight that entire table, in one go, then right click .... Copy.  In a new post, right click .... Paste.  That should paste in the entire table, as it appears in the modem.  That table will copy and paste, just like any other document table. That's the starting point, to see if there's anything obvious in the signal data. 

[dlee1919]

I really appreciate your time on this. Thanks so much.

Here you go:

Software Version

2.0.10.36T6

Downstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Signal noise ratio (dB)
1	609000000	256QAM	-6.500	7	38.983
10	303000000	256QAM	-9.200	1	38.605
11	579000000	256QAM	-8.300	2	38.605
12	585000000	256QAM	-7.800	3	38.605
13	591000000	256QAM	-7.300	4	38.983
14	597000000	256QAM	-7.300	5	38.983
15	603000000	256QAM	-7.200	6	38.983
16	615000000	256QAM	-6.600	8	38.983
17	621000000	256QAM	-6.700	9	40.366
18	633000000	256QAM	-7.200	10	38.605
19	639000000	256QAM	-7.400	11	38.983
20	645000000	256QAM	-7.600	12	38.605
21	651000000	256QAM	-7.200	13	38.983
22	657000000	256QAM	-7.000	14	38.605
23	663000000	256QAM	-6.500	15	38.605
24	669000000	256QAM	-5.300	16	38.983
25	675000000	256QAM	-4.700	17	38.983
26	681000000	256QAM	-4.800	18	38.983
27	687000000	256QAM	-4.900	19	38.983
28	693000000	256QAM	-4.700	20	40.366
29	699000000	256QAM	-5.000	21	38.983
30	705000000	256QAM	-5.000	22	38.983
31	711000000	256QAM	-5.600	23	38.983
32	861000000	256QAM	-8.100	24	38.605

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	287600000	YES	YES	YES	-8.000000

Upstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Bandwidth
1	30596000	ATDMA - 64QAM	43.250	3	6400000
2	36996000	ATDMA - 64QAM	43.250	4	6400000
3	22100000	ATDMA - 64QAM	45.500	1	3200000
4	25300000	ATDMA - 64QAM	45.750	2	3200000

OFDM/OFDMA Overview

Channel Index	State	lin Digital Att	Digital Att	BW (sc's*fft)	Report Power	Report Power1_6	FFT Size
0	DISABLED	0.5000	0.0000	0.0000	-inf	-1.0000	4K
1	DISABLED	0.5000	0.0000	0.0000	-inf	-1.0000	4K

[Datalink]

Ok, all of the downstream DOCSIS 3.0 channels (1 to 32) are low, in terms of their signal level, still within spec, but low.  Signal to noise ratios are ok.  

The downstream OFDM channel, which the modem uses for its downstream data is probably low as well, but the data to determine that is not shown in the user interface.  Tech support has access to that data.  

The upstream signal levels are higher than normal for this modem when its running the downstream OFDM channel.  Typically those levels are in the 30 to 32 dBmV range.  So, there is something afoot, so to speak. 

The upstream OFDMA channel isn't enabled yet. 

When you have the time and patience, call tech support and ask the Customer Service Rep to run a signal check on the modem.  Ask specifically if the downstream OFDM parameters are within spec and ask for that data.  It should include the:

1.  Signal level

2.  Signal to noise ratio

3.  The QAM level.    (It should be 1024.  Anything less indicates that the modem is not running its maximum data rate)

The problem here might be that the modem is fighting to use the downstream OFDM channel and flips back and forth between the upper DOCSIS 3.0 channels and the OFDM channel.  For that reason, its important to know the OFDM channel numbers to see if the're well within spec, or boarderline.  The tech might give you a hard time about telling you the data, if so, ask for the manager or Tier II tech support.  Indicate that you're seeing service dropouts, so knowing specifically what the OFDM channel is running for numbers is important for troubleshooting purposes.  Please let me know how the conversation goes.  

One thing to note, even with good signal data, you can still end up with service dropouts due to a failing external cable and/or its connectors.  At the very least, you probably need a tech visit to inspect that external cable and its connectors.  Something as simple as  replacing a couple of connectors could resolve the issue.  You might need the whole cable replaced.  Normally with signal levels in spec, even if low or high, Rogers won't do anything, but, with service dropouts occurring, that should provide some impetus to arrange for a tech visit. 

[dlee1919]

Wow, that’s really interesting. I’ll do exactly as you’ve set out and I’ll let you know how it goes. Again, thanks very much.

[Datalink]

Ugh, apologies for the typos, corrected as required.  Next step, depending on that tech support indicates, is to run a ping test to the Cable Modem Termination System (CMTS), in order to quantify the packet loss that is occurring.  

One question that I forgot to ask, are you seeing service dropouts with both ethernet and wifi connected devices or one particular network, ethernet or wifi?  

Running a ping test to the CMTS will require an ethernet connected device. 

[Crwills]

I'm actually having exactly the same issue with similar setup, so I'm really interested in the information in this thread. Specifically, all of our devices are on wifi, and we have 1 PC and 1-2 phones that constantly drop the wifi connection for a few seconds and then reconnect. It's gotten worse lately - used to be every few hours, now it seems like multiple times an hour. The modem / router is very close to all devices, so this isn't a distance issue. Rogers said there are no signal issues, and as with the person above, sent out a technician who checked outside, confirmed no issues, and left - they can't come inside due to COVID.

Would love any other suggestions on how to possibly resolve this!

Thanks,

Craig

[dlee1919]

Hi again,

Further to your advice, I contacted Rogers and asked  the tech to run a signal check on the modem.  I asked specifically if the downstream OFDM parameters are within spec and ask for that data.

The reply was as follows. The format looked better on my screen, but I can't get it to paste in here better than this. Sorry if this makes for a tough read:

I have loaded your account on my end with the account number you provided and all the results on your modem are within spec.

The details are listed below.

1. Tx Power (dBmV): 41.5 42.3 42 Rx Power (dBmV): -0.5 0.5 0.7

2. SNR 38.9 40.3 40.9

3. OFDM CHANNEL 1 INFORMATION MER Avg (dB) MER STD (dB) MER 98 Percentile (dB) 37.21 1.3 34.75 min: 29 dB Frequency (MHz) Rx Power (dBmV) min: -12max: 12 dBmV Rx Margin (dBmV) 309 -3.2 -13.2 315 -2.2 -12.2 321 -2.2 -12.2 327 -1.9 -11.9

Min/Max - qam256/qam4096 Modulation Max - Min Delta (dBmV) - 2.80 OFDM CM Rx Margin - TRUE

You also asked me whether I'm seeing service dropouts with both ethernet and wifi connected devices or one particular network, ethernet or wifi? My laptop doesn't have an ethernet port and I don't have the little converter that would let me plug in directly, so I'm always connected by wifi. My wife's laptop has a part, however, so I could connect that for troubleshooting purposes. She always uses hers via wifi only though.

[RogersTony]

Hello, @Crwills & @dlee1919

Welcome to the Rogers Community Forums!

An intermittent internet connection can become really disruptive. I know how important it is to have a consistent and reliable connection.

@Crwills - Wi-Fi can be affected by numerous factors like attenuation or interference. Have you tried doing a scan of the Wi-Fi networks in your home using a Wi-Fi Analyzer app? It can help determine if there is congestion on the channel that your modem is using. Where is the modem located in your home, is it in a central location?

@dlee1919 - Can you confirm if the light pattern on the modem changes when the connection drops? Since you are unable to confirm if the Ethernet connection drops also we will need to confirm if the modem is dropping the signal as well. The light pattern should have one green light followed by two blue lights and then one green light below when the modem is online.

If the modem is not going offline then the issue is most likely Wi-Fi network related. We'll need to confirm this to ensure we are troubleshooting this issue properly. 

We look forward to your response.

RogersTony

[Webb21]

Turns out I was right all along! Second tech came out and found a break in the wire outside, not inside like the other tech said. Since the new line went in no further issues and my cable tv even works better!!!