Download/Upload speed is dropping to 10mbps up/down daily

[user-v5]

I am on the 500mbps internet service tier.  My internet connection was frequently dropping for 5-10 seconds, about 1-3 times a day. Download/Upload speed was also dropping down to 10mbps across all devices, with high latency.  I replaced the cable modem(CODA -4582 with CODA -4582 v1A and firmware v7.1.1.37), and that took care of the frequent drops. But the issue with speed dropping down to 10mbps and high latency is still happening. Rebooting the modem resolves the issue temporarily, but it always returns.

I am running my modem in bridge mode with an wrt3200acm router. I ruled out my router by rebooting the router only(saw the same speed on my devices after reboot), trying to download a file directly on the router via a shell and watching the speed, and plugging in the wan ethernet cable into an old router I had laying around and using that instead(same speed). I have tightened and swapped every cable involved in the chain.

My home phone modem is in the same room, so there is a two port splitter(rogers provided Antronix splitter) between the wall and the cable modem. I unfortunately cannot move the cable modem or home phone modem to any other location in the house.

I am not sure if it is still a modem issue, or a signal issue.  Can someone confirm? The same thing is happening right now, and this is what I am seeing (updated signal logs after cable modem reboot are in the next post):

DOCSIS WAN

Downstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Signal noise ratio (dB)
1	663000000	QAM256	1.099	18	40.946
2	591000000	QAM256	1.500	7	40.946
3	597000000	QAM256	1.099	8	40.946
4	603000000	QAM256	0.799	9	40.946
5	849000000	QAM256	-0.700	2	38.983
6	855000000	QAM256	-1.900	3	38.983
7	861000000	QAM256	-2.700	4	38.983
8	579000000	QAM256	1.299	5	40.366
9	585000000	QAM256	1.299	6	40.366
10	609000000	QAM256	0.900	10	40.366
11	615000000	QAM256	0.900	11	40.366
12	621000000	QAM256	0.799	12	40.366
13	633000000	QAM256	1.299	13	40.946
14	639000000	QAM256	0.700	14	38.983
15	645000000	QAM256	0.500	15	40.366
16	651000000	QAM256	0.799	16	40.366
17	657000000	QAM256	0.700	17	40.366
18	279000000	QAM256	-2.599	1	38.983
19	669000000	QAM256	1.200	19	40.366
20	675000000	QAM256	1.099	20	40.366
21	681000000	QAM256	0.799	21	40.366
22	687000000	QAM256	0.700	22	40.366
23	693000000	QAM256	0.400	23	40.946
24	699000000	QAM256	0.799	24	40.366
25	705000000	QAM256	1.000	25	40.946
26	711000000	QAM256	0.500	26	40.946
27	717000000	QAM256	1.099	27	40.366
28	723000000	QAM256	1.200	28	40.366
29	825000000	QAM256	1.500	29	40.366
30	831000000	QAM256	1.299	30	40.946
31	837000000	QAM256	1.099	31	40.366
32	843000000	QAM256	0.099	32	40.366

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	-5.700001

Upstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Bandwidth
1	21100000	64QAM	48.760	1	3200000
2	38700000	64QAM	48.770	4	6400000
3	32300000	64QAM	48.770	3	6400000
4	25900000	64QAM	49.270	2	6400000
5	0	QAM_NONE	-	---	1600000
6	0	QAM_NONE	-	---	1600000
7	0	QAM_NONE	-	---	1600000
8	0	QAM_NONE	-	---	1600000

OFDM/OFDMA Overview

Channel Index	State	lin Digital Att	Digital Att	BW (sc's*fft)	Report Power	Report Power1_6	FFT Size
0	DISABLED	0.0000	0.0000	0.0000	0.0000	0.0000	2K
1	DISABLED	0.0000	0.0000	0.0000	0.0000	0.0000	2K

***Edited Labels***

[user-v5]

Just rebooted the cable modem, and my connection is back to normal with 742.8 mbps download, 22 mbps upload (according to rogers speed test). This is what the signal readings after like after the cable modem(they look the same as before the reboot?):

DOCSIS Logs

The DOCSIS event logs are shown here

(Log file removed for privacy reasons. Please edit the CM MAC address before uploading the log file. - RogersMoin)

DOCSIS WAN

Downstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Signal noise ratio (dB)
1	663000000	QAM256	1.099	18	40.366
2	591000000	QAM256	1.400	7	40.946
3	597000000	QAM256	1.000	8	40.366
4	603000000	QAM256	0.799	9	40.946
5	849000000	QAM256	-0.799	2	38.983
6	855000000	QAM256	-1.900	3	38.983
7	861000000	QAM256	-2.700	4	38.605
8	579000000	QAM256	1.200	5	40.946
9	585000000	QAM256	1.299	6	40.366
10	609000000	QAM256	0.799	10	40.946
11	615000000	QAM256	0.799	11	40.366
12	621000000	QAM256	0.799	12	40.366
13	633000000	QAM256	1.200	13	40.366
14	639000000	QAM256	0.599	14	38.983
15	645000000	QAM256	0.500	15	38.983
16	651000000	QAM256	0.799	16	40.366
17	657000000	QAM256	0.599	17	40.366
18	279000000	QAM256	-2.599	1	38.983
19	669000000	QAM256	1.200	19	40.366
20	675000000	QAM256	1.200	20	40.366
21	681000000	QAM256	0.799	21	40.366
22	687000000	QAM256	0.599	22	40.366
23	693000000	QAM256	0.400	23	40.366
24	699000000	QAM256	0.799	24	40.946
25	705000000	QAM256	1.000	25	40.366
26	711000000	QAM256	0.500	26	40.366
27	717000000	QAM256	1.099	27	40.366
28	723000000	QAM256	1.099	28	40.946
29	825000000	QAM256	1.500	29	40.366
30	831000000	QAM256	1.299	30	40.366
31	837000000	QAM256	1.000	31	40.366
32	843000000	QAM256	0.099	32	40.366

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	-5.700001

Upstream Overview

Port ID	Frequency (MHz)	Modulation	Signal strength (dBmV)	Channel ID	Bandwidth
1	21100000	64QAM	47.760	1	3200000
2	38700000	64QAM	48.770	4	6400000
3	32300000	64QAM	48.770	3	6400000
4	25900000	64QAM	48.770	2	6400000
5	0	QAM_NONE	-	---	1600000
6	0	QAM_NONE	-	---	1600000
7	0	QAM_NONE	-	---	1600000
8	0	QAM_NONE	-	---	1600000

OFDM/OFDMA Overview

Channel Index	State	lin Digital Att	Digital Att	BW (sc's*fft)	Report Power	Report Power1_6	FFT Size
0	DISABLED	0.0000	0.0000	0.0000	0.0000	0.0000	2K
1	DISABLED	0.0000	0.0000	0.0000	0.0000	0.0000	2K

[Bridge_broken]

I'm having this exact same issue. Rogers technical support told me to try new cables but that didn't solve the issue. It's very frustrating..

[user-v5]

My issue still isn't resolved. I am going to try swapping modems again. I have been very patient, but I have had enough. If this issue is not resolved, I am going to be moving over to bell fibe.

[RogersMoin]

Hello, @user-v5.

I appreciate you rejoining the thread; it may not be modem related issue. Have you worked with tech support in the past six months? 

We can investigate your speed dropping to 10 Mbps concern. Please send us a private message at @CommunityHelps. You can find details about our private messaging in this blog.

Cheers,

RogersMoin

[-G-]

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@user-v5 wrote:

My issue still isn't resolved. I am going to try swapping modems again. I have been very patient, but I have had enough. If this issue is not resolved, I am going to be moving over to bell fibe.

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By any chance, are you running OpenWrt 22.03 on your WRT3200ACM?