Netgear CM1000v2 RCN/Astound Connection Drops

[ctsuhako]

Hello:

I have been having recent issues with constant connection dropouts and extreme lag with RCN/Astound with my Netgear CM1000v2 cable modem. Am seeing a lot of notices like this:

Dynamic Range Window violation
2023-07-12, 23:40:25	Warning (5)	RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=94:a6:7e:0d:c5:54;CMTS-MAC=00:af:1f:1e:b1:5a;CM-QOS=1.1;CM-VER=3.1;
2023-07-12, 23:33:56	Warning (5)	DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=94:a6:7e:0d:c5:54;CMTS-MAC=00:af:1f:1e:b1:5a;CM-QOS=1.1;CM-VER=3.1;
2023-07-12, 23:33:56	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: 1 3 4; New Profile: 1 2 3.;CM-MAC=94:a6:7e:0d:c5:54;CMTS-MAC=00:af:1f:1e:b1:5a;CM-QOS=1.1;CM-VER=3.1;

RCN/Astound has reset the modem and they have apparently changed their policies on BYOM where they cannot do any type of troubleshooting.

Here is the cable connection data. I really don't know what to look for and they will charge me $75 to come look at it. Thank you.

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Frequency start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency 501000000

Procedure	Status	Comment
Acquire Downstream Channel	501000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv4 only

---

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	18	501000000 Hz	3.7 dBmV	34.2 dB	288390124	21399	31867
2	Locked	QAM256	1	519000000 Hz	3.5 dBmV	34.0 dB	287424749	19017	28980
3	Locked	QAM256	2	525000000 Hz	3.5 dBmV	33.9 dB	287429991	19053	27703
4	Locked	QAM256	3	531000000 Hz	3.5 dBmV	33.8 dB	122903526	5753	14003
5	Locked	QAM256	4	537000000 Hz	3.4 dBmV	33.7 dB	287440795	16897	26223
6	Locked	QAM256	5	543000000 Hz	3.1 dBmV	33.7 dB	287435313	15757	25869
7	Locked	QAM256	6	549000000 Hz	2.8 dBmV	33.6 dB	287450049	15349	25312
8	Locked	QAM256	7	555000000 Hz	2.5 dBmV	33.6 dB	91466254	4102	9488
9	Locked	QAM256	8	561000000 Hz	2.5 dBmV	32.9 dB	287454146	16975	27032
10	Locked	QAM256	9	567000000 Hz	2.4 dBmV	33.6 dB	287459908	15989	26432
11	Locked	QAM256	10	573000000 Hz	2.5 dBmV	33.6 dB	287464515	16003	25587
12	Locked	QAM256	11	579000000 Hz	2.8 dBmV	37.4 dB	287469962	15257	24129
13	Locked	QAM256	12	585000000 Hz	4.0 dBmV	38.6 dB	287476512	14106	22621
14	Locked	QAM256	13	591000000 Hz	3.1 dBmV	34.6 dB	287482478	13150	21383
15	Locked	QAM256	14	597000000 Hz	3.1 dBmV	34.5 dB	287485829	12569	22207
16	Locked	QAM256	15	603000000 Hz	2.9 dBmV	34.4 dB	287487340	13698	23245
17	Locked	QAM256	16	609000000 Hz	2.6 dBmV	34.3 dB	287488835	14436	24788
18	Locked	QAM256	17	495000000 Hz	3.7 dBmV	34.1 dB	287477445	22255	32288
19	Locked	QAM256	19	507000000 Hz	3.6 dBmV	34.0 dB	287481954	20441	30530
20	Locked	QAM256	20	513000000 Hz	3.5 dBmV	33.8 dB	287495457	20090	29903
21	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
22	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
23	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
24	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
25	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
26	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
27	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
28	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
29	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
30	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
31	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

---

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	36800000 Hz	44.0 dBmV
2	Locked	ATDMA	2	30350000 Hz	46.0 dBmV
3	Locked	ATDMA	3	23900000 Hz	43.5 dBmV
4	Not Locked	Unknown	0	0 Hz	0.0 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Hz	0.0 dBmV

---

Downstream OFDM Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power	SNR / MER	Active Subcarrier Number Range	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	0, 1, 2, 3	159	682000000 Hz	2.2 dBmV	30.0 dB	166 ~ 3929	314613111	72722389	4811
2	Not Locked	0	0	0 Hz	1.5 dBmV	0.0 dB	0 ~ 4095	0	0	0

---

Upstream OFDMA Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power
1	Not Locked	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

[FURRYe38 · Accepted solution]

Glad you got it working. Please mark your thread as solved so others will know. 
Enjoy. 📡

[FURRYe38]

What speeds do you pay for UP and Down from the ISP?

Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.

Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 
What is the brand and model of the host wifi router connected to the modem?

The modem has a ton of Correctables and Un-correctables that should be zeros. 

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/

[ctsuhako]

400 Mbps up and 25 Mbps down.

Finally got a hold of someone knowledgable at Astound/RCN (via Twitter). After checking they rebalanced the connection as they said the signal strength was too low. Everything seems back to normal. Twitter is still good for something.

[FURRYe38 · Accepted solution]

Glad you got it working. Please mark your thread as solved so others will know. 
Enjoy. 📡