Download speed keeps dropping overnight, only a reboot restores it. CODA 4582U

[pchrzan]

Have had this problem for some time now. I have to reboot the modem daily to get speeds back to 300 mbps. As soon as it reboots its fine for a few hours of testing. Then overnight and in the morning I'm back down to 30 mbps or less. No changes in modem settings have worked, have tried with and without a router, and with bridged mode and as access point. Any idea why this occurs?  I have a few devices connected (NEST thermostat, TV, xbox one, phones, and computer).

Lease Time

😧 06 H: 01 M: 54 S: 55

Downstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Signal noise ratio (dB)
1	669000000	256QAM	-11.400	19	27.356
19	279000000	256QAM	-0.200	1	28.224
20	675000000	256QAM	-11.600	20	27.249
22	687000000	256QAM	-12.300	22	27.067

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	NA	NA	NO	NO	NO	NA

Upstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Bandwidth
1	22100000	ATDMA - 64QAM	38.500	1	3200000
2	36996000	ATDMA - 64QAM	38.750	4	6400000
3	30596000	ATDMA - 64QAM	40.500	3	6400000
4	25300000	ATDMA - 64QAM	40.250	2	3200000

[Datalink]

@pchrzan is that the entire signal table??  If so, you only have 4 DOCSIS 3.0 downstream channels available for use.  There should be 32 channels.  Three of those channels shown are below the -10 dBmV cut off point where Rogers will dispatch a tech.  The rest are missing, which will definitely require a tech to fix.

Your modem isn't running the DOCSIS 3.1 OFDM channel, which it normally uses for its downstream data.  When that happens the modem will then use the upper DOCSIS 3.0 channels, where in this case, a good number of them are missing.

Your upstream DOCSIS 3.0 channels are too bad although their higher than normal for this modem. Typically you will see upstream power levels in the 30 to 32 dBmV range. 

In short, you need a field tech to check the external cables and connectors and fix/replace both.  Call tech support and advise the Customer Service Rep that you only have 4 downstream DOCSIS 3.0 channels running and that the DOCSIS 3.1 OFDM channel isn't running at all.  Ask him or her to run a signal check on the modem.  It will fail automatically.  That should be followed by  discussion to arrange for a tech visit.  Your external cable system has severe problems in the 200 to 1002 Mhz range, to the point that several channels are missing and the DOCSIS 3.1 OFDM channel isn't running.  

If the tech asks you to reboot the modem, at which point the signal levels will normally return to normal, and then he or she declares victory, don't believe it.  That's just a temporary fix as you have already noted, but it doesn't resolve the underlying cable problem.  Seems that some techs will do that but all it does is kick the can down the road for some other tech to deal with.  So, you need a field tech to determine what the problem is.  The external cables don't last forever, and every once in a while have to be replace, along with their connectors.  So, the field tech has to determine what condition the cable is in, and while he or she is there, replace the connectors.  The cable replacement will depend on the condition of the cable.  

After the tech has come and gone, please repost the entire signal level table.  If you still have problems, don't hesitate to call tech support and complain about poor cable service. 

[pchrzan]

That is the entire table i see right now (i did not reboot after last night yet). I currently have it in bridge mode (does that affect the missing data?)

[Datalink]

Nope.  It doesn't matter what mode the modem is using, Gateway or Bridge mode, the results will be the same.

Don't reboot the modem before you call tech support, leave it as is for now.

Edit: Correction to my post above;

"Your upstream DOCSIS 3.0 channels are too bad although their higher than normal for this modem. Typically you will see upstream power levels in the 30 to 32 dBmV range. "

should read:

Your upstream DOCSIS 3.0 channels are't too bad although their higher than normal for this modem. Typically you will see upstream power levels in the 30 to 32 dBmV range. 

Apologies for the confusion 😞

[Jawed]

I was having similar problems a while ago. I called Rogers, they sent a technician, he couldn’t diagnose anything, he sent a senior technician, he also couldn’t find an issue. I just ended up changing my modem. Which fixed the issue. They apparently recommend that you switch modems every six months.

[Datalink]

If a reboot brings your internet service back up, that's usually an external cable and/or connector issue at fault. 

Changing modems every 6 months is a completely nutty recommendation.  If every customer did that it would probably overwhelm the company's logistics system.  Rogers has about 2.5 million broadband subscribers according to its own reports, so, divide by 365 days per year gives you 6,849.3 modems per day, multiply by twice per year, that was recommended and you end up with 13,698.6 modems per day that would need changing.  Rogers has about 417,000 Ignite TV subscribers with the XB6 modem, so if their not included as part of the original 2.5 million number, running the same calculation adds another 2, 284.9 modems per day that would require changing.  Not gonna happen, no way, no how.  The modems are actually pretty reliable, with serviceability rates in the upper 90% range, so, every once in a while you will end up with an unserviceable modem.  It can certainly happen, but not to the extent that was indicated to you.   Not supporting Rogers on this, and, I don't work for Rogers in any way, shape or form, but, the recommendation as stated just doesn't make any sense.  Just trying to put some logical thinking in place here 😞

Fwiw my 4582 has been in use now for over 3 years now without any problems since it was received.