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Forum Discussion
CM1000v2 keeps disconnecting, high uncorrectable codewords
I've been trying to stop my internet (800Mbps xfinity) from disconnecting periodically. It works fine for a long period, but then it disconnects relentlessly and I disconnect/restart both the modem and router to get the internet to work again. I called xfinity to check the line and the coax within the house and they say that everything from the cable connection is working fine and that if anything was wrong their diagnostic tool would report a percentage error worth fixing. The internet speed tests are all over the place, when I perform a test one day via phone it could read 240 Mbps and on a wired connection it could read 88 Mbps. I connect to the modem through a Netgear R6220.
| 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. | |
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<tabindex=-1>Startup Procedure</tabindex=-1>
| Procedure | Status | Comment |
| Acquire Downstream Channel | 411000000 Hz | Locked |
| Connectivity State | OK | Operational |
| Boot State | OK | Operational |
| Security | Enable | BPI+ |
| IP Provisioning Mode | Honor MDD | IPv6 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 | 4 | 411000000 Hz | -3.2 dBmV | 41.0 dB | 224299144 | 4094054 | 13293698 |
| 2 | Locked | QAM256 | 5 | 417000000 Hz | -3.0 dBmV | 41.3 dB | 216466653 | 3863471 | 12670536 |
| 3 | Locked | QAM256 | 6 | 435000000 Hz | -2.2 dBmV | 41.6 dB | 227498689 | 4017606 | 13592850 |
| 4 | Locked | QAM256 | 7 | 441000000 Hz | -3.1 dBmV | 41.0 dB | 244708927 | 4220263 | 14456158 |
| 5 | Locked | QAM256 | 8 | 453000000 Hz | -2.9 dBmV | 41.1 dB | 211607499 | 3812795 | 13101299 |
| 6 | Locked | QAM256 | 9 | 459000000 Hz | -2.2 dBmV | 41.5 dB | 209611145 | 3609816 | 12545188 |
| 7 | Locked | QAM256 | 10 | 465000000 Hz | -3.2 dBmV | 41.0 dB | 219617394 | 3879765 | 13520360 |
| 8 | Locked | QAM256 | 11 | 471000000 Hz | -2.9 dBmV | 41.2 dB | 230975752 | 4053955 | 14211023 |
| 9 | Locked | QAM256 | 12 | 477000000 Hz | -3.0 dBmV | 41.2 dB | 240162899 | 4123029 | 14609499 |
| 10 | Locked | QAM256 | 13 | 483000000 Hz | -3.1 dBmV | 41.0 dB | 212233598 | 3723894 | 13115585 |
| 11 | Locked | QAM256 | 14 | 489000000 Hz | -2.2 dBmV | 41.7 dB | 212511269 | 3690870 | 13042231 |
| 12 | Locked | QAM256 | 15 | 495000000 Hz | -3.2 dBmV | 41.0 dB | 197787620 | 3469865 | 12241545 |
| 13 | Locked | QAM256 | 16 | 501000000 Hz | -2.9 dBmV | 41.1 dB | 204399181 | 3573653 | 12687555 |
| 14 | Locked | QAM256 | 17 | 507000000 Hz | -3.3 dBmV | 41.0 dB | 210242868 | 3684047 | 13142852 |
| 15 | Locked | QAM256 | 18 | 513000000 Hz | -3.1 dBmV | 40.9 dB | 259895599 | 4416310 | 15891449 |
| 16 | Locked | QAM256 | 19 | 519000000 Hz | -3.1 dBmV | 40.8 dB | 262331915 | 4452113 | 16074550 |
| 17 | Locked | QAM256 | 20 | 525000000 Hz | -4.0 dBmV | 40.4 dB | 224855095 | 3807468 | 13772962 |
| 18 | Locked | QAM256 | 21 | 531000000 Hz | -3.1 dBmV | 40.9 dB | 232394900 | 3957625 | 14295868 |
| 19 | Locked | QAM256 | 22 | 537000000 Hz | -3.2 dBmV | 40.8 dB | 215458908 | 3804115 | 13711959 |
| 20 | Locked | QAM256 | 23 | 543000000 Hz | -2.3 dBmV | 41.3 dB | 220934479 | 3788297 | 13713035 |
| 21 | Locked | QAM256 | 24 | 549000000 Hz | -3.5 dBmV | 40.5 dB | 245520684 | 4164670 | 15165937 |
| 22 | Locked | QAM256 | 25 | 555000000 Hz | -3.4 dBmV | 40.8 dB | 249109777 | 4209214 | 15369551 |
| 23 | Locked | QAM256 | 26 | 561000000 Hz | -3.2 dBmV | 40.8 dB | 245243495 | 4144220 | 15141352 |
| 24 | Locked | QAM256 | 27 | 567000000 Hz | -3.0 dBmV | 40.9 dB | 219494204 | 3803712 | 13884071 |
| 25 | Locked | QAM256 | 28 | 573000000 Hz | -2.2 dBmV | 41.3 dB | 228669520 | 3911250 | 14301543 |
| 26 | Locked | QAM256 | 29 | 579000000 Hz | -3.8 dBmV | 40.3 dB | 217860670 | 3761191 | 13736947 |
| 27 | Locked | QAM256 | 30 | 585000000 Hz | -2.4 dBmV | 41.1 dB | 211748691 | 3608226 | 13193808 |
| 28 | Locked | QAM256 | 31 | 591000000 Hz | -3.2 dBmV | 40.7 dB | 234831278 | 4005884 | 14729240 |
| 29 | Locked | QAM256 | 32 | 597000000 Hz | -2.6 dBmV | 40.9 dB | 175358192 | 3078938 | 11272495 |
| 30 | Locked | QAM256 | 33 | 603000000 Hz | -2.9 dBmV | 40.9 dB | 215723968 | 3637391 | 13441123 |
| 31 | Locked | QAM256 | 34 | 609000000 Hz | -3.7 dBmV | 40.4 dB | 230213948 | 3845796 | 14196836 |
| 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 | 10400000 Hz | 47.8 dBmV |
| 2 | Locked | ATDMA | 2 | 16400000 Hz | 47.8 dBmV |
| 3 | Locked | ATDMA | 3 | 22800000 Hz | 47.5 dBmV |
| 4 | Locked | ATDMA | 4 | 29200000 Hz | 47.5 dBmV |
| 5 | Locked | ATDMA | 5 | 35600000 Hz | 46.3 dBmV |
| 6 | Locked | ATDMA | 11 | 40400000 Hz | 49.3 dBmV |
| 7 | Not Locked | Unknown | 0 | 0 Hz | 0.0 dBmV |
| 8 | Not Locked | Unknown | 0 | 0 Hz | 0.0 dBmV |
<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
| 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 | 48 | 722000000 Hz | -4.7 dBmV | 37.8 dB | 1108 ~ 2987 | 120471615 | 111320056 | 546739 |
| 2 | Not Locked | 0 | 0 | 0 Hz | -3.5 dBmV | 0.0 dB | 0 ~ 4095 | 0 | 0 | 0 |
<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
| 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 |
Current System Time: Fri Jun 09 14:21:52 2023 System Up Time: 1:47:32
| 2023-06-09, 20:22:16 | Notice (6) | CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:21:23 | Notice (6) | CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1 |
| 2023-06-09, 20:21:12 | Warning (5) | MDD message timeout;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:20:28 | Notice (6) | CM-STATUS message sent. Event Type Code: 5; Chan ID: 7 12 14 18 19 20 21 24 25 26 27 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:20:25 | Notice (6) | CM-STATUS message sent. Event Type Code: 2; Chan ID: 14; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:18:02 | Notice (6) | CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2 3.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:17:21 | Critical (3) | Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:16:59 | Notice (6) | CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1 |
| 2023-06-09, 20:16:39 | Warning (5) | MDD message timeout;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:16:37 | Notice (6) | CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1 |
| 2023-06-09, 20:16:23 | Warning (5) | MDD message timeout;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:16:10 | Notice (6) | CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:16:05 | Notice (6) | CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1 |
| 2023-06-09, 20:15:42 | Warning (5) | MDD message timeout;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1;CM-VER=3.1; |
| 2023-06-09, 20:15:19 | Notice (6) | CM-STATUS message sent. Event Type Code: 4; Chan ID: 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=6c:cd:d6:92:3c:44;CMTS-MAC=00:01:5c:a8:78:4d;CM-QOS=1.1 |
3 Replies
Any Criticals, Errors or Warnings in the event logs needs to be reviewed by the ISP. These indicate a signal line issue from the ISP up to the modem.
You have tons of correctables and un-correctables that should be zeros.
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended.
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-Modems/m-p/1530376#M12853
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/Also note you have only 31 channels downstream and you should have 32.
Kitsap Not uncommon to see the ISP not lock the 32'd channel and use the ofdma channel (3.1) as the 32'd channel.
They are correct in that you have a ton of errors. Check your line first and if it doesn't help, then have the ISP check it.
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.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISP’s charge if the wiring issue is in the home. So this helps prevent this.
