internet flapping several times per day.

[zhouzhilong]

Not sure if anyone can help me. My home internet keep flapping several times per day for years. I am using Rogers modem CODA-4582U.
Originally I think it's modem issue, so I changed it from Rogers, things still the same ,   I start to use Rogers router as modem and bough ASUS AC 5300, same thing, then I bought AC3100， still the same thing. I am wondering if any professional can take a look to see if something wrong with signal below, much appreciated your help.

Downstream Overview
Port ID Frequency (MHz) Modulation Signal strength (dBmV) Channel ID Signal noise ratio (dB)
1 591000000 256QAM 2.600 7 38.983
2 597000000 256QAM 3.000 8 40.366
3 603000000 256QAM 2.400 9 38.605
4 579000000 256QAM 0.200 5 38.605
5 597000000 64QAM 1.900 6 4.191
6 603000000 256QAM 2.400 1 4.243
7 609000000 64QAM 1.200 10 4.191
8 615000000 256QAM 0.200 11 40.366
9 621000000 256QAM 0.900 12 38.983
10 633000000 256QAM 1.800 13 40.946
11 639000000 256QAM 1.300 14 38.983
12 645000000 256QAM 1.700 15 40.366
13 651000000 256QAM 1.200 16 40.366
14 579000000 256QAM 1.000 17 4.243
15 585000000 64QAM 1.000 18 4.191
16 591000000 64QAM 1.500 19 4.191
17 675000000 256QAM 1.000 20 38.983
18 681000000 256QAM 0.800 21 38.983
19 687000000 256QAM 1.400 22 38.983
20 693000000 256QAM 1.300 23 38.983
21 699000000 256QAM 1.300 24 38.983
22 705000000 256QAM 1.600 25 40.366
23 711000000 256QAM 1.300 26 38.983
24 717000000 256QAM 1.300 27 40.366
25 723000000 256QAM 1.600 28 38.983
26 825000000 256QAM 1.500 29 38.605
27 831000000 256QAM 1.000 30 38.983
28 837000000 256QAM 0.800 31 38.605
29 843000000 256QAM 0.400 32 38.983
30 849000000 256QAM 0.400 2 38.605
31 855000000 256QAM -0.500 3 38.605
32 861000000 256QAM -1.500 4 38.605
OFDM Downstream Overview
Receiver FFT type Subcarr 0 Frequency(MHz) PLC locked NCP locked MDC1 locked PLC power(dBmv)
Upstream Overview
Port ID Frequency (MHz) Modulation Signal strength (dBmV) Channel ID Bandwidth
1 30596000 ATDMA - 64QAM 27.500 4 6400000
2 38596000 ATDMA - 64QAM 32.750 6 3200000
3 23700000 ATDMA - 64QAM 27.250 5 6400000
OFDM/OFDMA Overview
Channel Index State lin Digital Att Digital Att BW (sc's*fft) Report Power Report Power1_6
FFT Size
HW init Success
Find Downstream Success
Ranging Success
DHCP Success
Time of Day Success
Download CM Config File Success
Registration Success
EAE status Disable
BPI status AUTH:authorized, TEK:operational
The DOCSIS event logs is shown here
(Log removed for security/privacy reasons - RogersMoin)

*Added Labels*

[Datalink]

@zhouzhilong can you delete the data above the Downstream Overview please, as well as the numerical string following the "CM-MAC=xx.xx.xx.xx.xx.xx" address, which is the modem's MAC address.

Looking at the signal levels, looks like you have a noise issue as some of the DOCSIS 3.0 channels are running at 64 QAM instead of 256.  

The OFDM channel, which this modem runs is situated in the 300 to 500 Mhz range.  Did you copy the entire table all in one go?  If so, then the modem isn't running the OFDM channel as it should be, so the modem would be relying on the upper DOCSIS 3.0 channels for the downstream data.  

The upstream DOCSIS 3.0 channels are a little low, but, the measure of success is whether or not those upstream channels are satisfactory when they arrive at the Cable Modem Termination System, which controls and provides data services to the modem.  Those numbers aren't reported back to the modem, so the end user has to call tech support to determine if the upstream channel signal levels and signal to noise ratios are adequate at the CMTS.  

If you don't have one OFDM Downstream channels running, then you have signal problems in the 200 to 500 Mhz range.  If thats the case call tech support and ask the Customer Service Rep to run a signal check on the modem.  Don't reboot the modem prior to the call.  Leave it exactly as it is.  With the OFDM channel not running, that signal check should fail automatically.  My guess would be that the modem is attempting to use that OFDM channel and failing those attempts due to the cable signal issue within the OFDM frequency range, falling back on the upper DOCSIS 3.0 channels which also have signal problems.  Any noticeable drop in performance is probably occurring at the start of the attempt to use the OFDM channel, followed by a switch back to the DOCSIS 3.0 channels.

Advise the CSR that you don't have a DOCSIS 3.1 OFDM channel running and that you have some DOCSIS 3.0 channels running 64 QAM instead of 256 QAM.  Those channels are located around 590 Mhz.  So, what ever the problem is in the 200 to 500 Mhz band is going as high as 600 Mhz.  That should grab the techs attention and force him or her to actually look at the data instead of relying on a simple go / no go check. 

There simply isn't enough data presented to be able to understand what the problem is in that 200 to 600 Mhz band, so, you will need a tech to check your external cable and connectors.  An automatic failure of the signal check should result in the CSR arranging for a tech visit at your convenience to resolve the problem. 

When that is done, can you repost that entire table, from the Downstream Overview title, all the way to the bottom of the bottom OFDM/OFDMA section.  

[cafekief]

What app are u using or website?