CM1100 need to reset modem constantly with COX

[Larry2024]

Hi all, used to be every few days but now I am having to reset the modem multiple times a day and it is driving me nuts.  Here is the connection after a factory reset.  Many thanks!

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 855000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enable BPI+ IP Provisioning Mode Honor MDD IPv4 only

Downstream Bonded Channels (Partial Service)

Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 21 855000000 Hz -14.8 dBmV 32.5 dB 23050907 825 405 2 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0 3 Locked QAM256 7 771000000 Hz -11.0 dBmV 37.2 dB 21980037 316 125 4 Locked QAM256 8 777000000 Hz -12.0 dBmV 38.4 dB 19841836 1826 4438 5 Locked QAM256 9 783000000 Hz -11.5 dBmV 35.6 dB 19584299 1237 1601 6 Locked QAM256 10 789000000 Hz -12.0 dBmV 38.4 dB 21989947 1409 1794 7 Locked QAM256 11 795000000 Hz -12.8 dBmV 37.8 dB 21995225 324 117 8 Locked QAM256 12 801000000 Hz -12.0 dBmV 38.4 dB 21999242 356 145 9 Locked QAM256 13 807000000 Hz -13.0 dBmV 37.7 dB 22003836 351 172 10 Locked QAM256 14 813000000 Hz -13.0 dBmV 37.6 dB 22006003 416 196 11 Locked QAM256 15 819000000 Hz -12.9 dBmV 37.7 dB 22012145 333 179 12 Locked QAM256 16 825000000 Hz -14.3 dBmV 36.6 dB 22015422 358 138 13 Locked QAM256 25 117000000 Hz -1.1 dBmV 44.1 dB 19089780 6170 6918 14 Locked QAM256 26 123000000 Hz -1.7 dBmV 36.4 dB 19515744 7457 9133 15 Locked QAM256 27 129000000 Hz -1.8 dBmV 43.6 dB 18214646 6116 8634 16 Locked QAM256 28 135000000 Hz -2.5 dBmV 43.2 dB 18215535 9897 12248 17 Locked QAM256 29 141000000 Hz -3.2 dBmV 43.7 dB 6145808 4913 8362 18 Locked QAM256 30 147000000 Hz -3.1 dBmV 43.8 dB 9582364 12780 22982 19 Locked QAM256 31 153000000 Hz -3.4 dBmV 43.7 dB 4869351 2956 5084 20 Locked QAM256 32 159000000 Hz -2.7 dBmV 44.3 dB 7653978 8049 14270 21 Locked QAM256 33 165000000 Hz -2.9 dBmV 39.8 dB 8669753 6633 12321 22 Locked QAM256 34 171000000 Hz -2.9 dBmV 44.3 dB 9507847 6615 12718 23 Locked QAM256 35 177000000 Hz -2.8 dBmV 44.2 dB 22036461 11043 22196 24 Locked QAM256 36 183000000 Hz -3.2 dBmV 33.9 dB 18262007 6241 11163 25 Locked QAM256 37 189000000 Hz -3.1 dBmV 44.0 dB 5222269 2028 2576 26 Locked QAM256 38 195000000 Hz -3.3 dBmV 27.4 dB 2531622 2812 3198 27 Locked QAM256 39 201000000 Hz -3.3 dBmV 44.4 dB 8775821 4461 7863 28 Locked QAM256 40 207000000 Hz -3.4 dBmV 41.1 dB 22072957 7769 15987 29 Locked QAM256 41 213000000 Hz -3.1 dBmV 36.5 dB 8834414 22043 13062 30 Locked QAM256 42 219000000 Hz -3.3 dBmV 44.8 dB 19541181 6421 11580 31 Locked QAM256 43 225000000 Hz -3.3 dBmV 44.7 dB 10655923 5711 9550 32 Locked QAM256 45 237000000 Hz -3.6 dBmV 44.6 dB 8800598 3250 5339

Upstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 1 16900000 Hz 43.5 dBmV 2 Locked ATDMA 2 23500000 Hz 44.8 dBmV 3 Locked ATDMA 3 29900000 Hz 44.3 dBmV 4 Locked ATDMA 4 36300000 Hz 44.3 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 300000000 Hz -6.8 dBmV 40.8 dB 296 ~ 7895 87017631 14921224 29355 2 Locked 0, 1, 2, 3 160 918000000 Hz -16.2 dBmV 27.8 dB 1108 ~ 2987 6202832 4116078 1531209

Upstream OFDMA Channels

Channel Lock Status Modulation / Profile ID Channel ID Frequency Power 1 Locked 3, 4, 9, 10, 11, 12, 13 6 36800000 Hz 40.0 dBmV 2 Not Locked 3, 4, 9, 10, 11, 12, 13 0 0 Hz 0.0 dBmV

[FURRYe38 · Accepted solution]

Looks good. Some channels are a bit far in power between the channels however if it's working. Let it run. 

[Kitsap]

Your power levels are way low and you have a large number of correctable/uncorrectable code words.

The power levels should be between +7 dBmV and -7 dBmV.  For reference, see the top two sentences on this support document.  https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router

The next time you copy the connection status page, include the system up time.  The correctable/uncorrectable counts reset to zero when you boot the modem.  Not knowing how long it took your modem to reach the values indicated is a problem.

You have some serious line issues that need to be resolved by your ISP.  You can check your coax cable for damage, corroded or loose connections, old splitters, amplifiers, etc. that can negatively impact your signal.  Keep in mind, some of your issues could be house wiring your ISP would charge you to correct.

[Larry2024]

Thank you Kitsap,

I do have a Cox tech coming out tomorrow, but I'd like to understand the issue a little bit so thank you very much for taking the time to review this issue.

I don't know if there is a splitter in the box outside or not but there is only a F81 connector connecting the cables from the box and where the modem is located.  The wiring is original so 24 years old.

The connection up time when I posted was no more than 10 mins.

Here is the update connection status with system up time.  Way more correctable and uncorrectable codewords now.

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 855000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enable BPI+ IP Provisioning Mode Honor MDD IPv4 only

Downstream Bonded Channels (Partial Service)

Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 21 855000000 Hz -14.3 dBmV 35.5 dB 328693178 20636 22661 2 Locked QAM256 5 759000000 Hz -10.9 dBmV 27.4 dB 5774241 16536366 55567144 3 Locked QAM256 7 771000000 Hz -10.5 dBmV 39.0 dB 327638939 15273 15660 4 Locked QAM256 8 777000000 Hz -11.4 dBmV 38.9 dB 176077955 284318 574636 5 Locked QAM256 9 783000000 Hz -11.0 dBmV 39.2 dB 136105481 543275 1456156 6 Locked QAM256 10 789000000 Hz -11.5 dBmV 38.8 dB 327641674 23086 21979 7 Locked QAM256 11 795000000 Hz -12.2 dBmV 38.2 dB 327656367 16076 16748 8 Locked QAM256 12 801000000 Hz -11.5 dBmV 38.7 dB 327660263 15765 16277 9 Locked QAM256 13 807000000 Hz -12.4 dBmV 38.0 dB 327667349 15585 16455 10 Locked QAM256 14 813000000 Hz -12.5 dBmV 37.9 dB 327667045 15892 16786 11 Locked QAM256 15 819000000 Hz -12.4 dBmV 38.1 dB 327672400 16541 16954 12 Locked QAM256 16 825000000 Hz -13.7 dBmV 37.1 dB 327673214 17453 18275 13 Locked QAM256 25 117000000 Hz -1.0 dBmV 44.5 dB 56219001 63485 72081 14 Locked QAM256 26 123000000 Hz -1.5 dBmV 44.1 dB 174068536 155663 218077 15 Locked QAM256 27 129000000 Hz -1.7 dBmV 44.3 dB 41622214 42504 59304 16 Locked QAM256 28 135000000 Hz -2.5 dBmV 44.2 dB 67786450 143318 211413 17 Locked QAM256 29 141000000 Hz -3.2 dBmV 44.3 dB 82571893 184982 300014 18 Locked QAM256 30 147000000 Hz -3.1 dBmV 44.3 dB 98404555 197061 333097 19 Locked QAM256 31 153000000 Hz -3.4 dBmV 44.3 dB 118219532 257729 446135 20 Locked QAM256 32 159000000 Hz -2.7 dBmV 44.7 dB 127242183 242042 431759 21 Locked QAM256 33 165000000 Hz -3.0 dBmV 42.4 dB 71911075 189290 368675 22 Locked QAM256 34 171000000 Hz -2.9 dBmV 44.6 dB 57851126 116772 198712 23 Locked QAM256 35 177000000 Hz -2.8 dBmV 44.7 dB 69636261 104833 226957 24 Locked QAM256 36 183000000 Hz -3.1 dBmV 37.0 dB 79070806 115492 291264 25 Locked QAM256 37 189000000 Hz -2.9 dBmV 44.5 dB 32298940 99232 262118 26 Locked QAM256 38 195000000 Hz -3.2 dBmV 32.8 dB 48665320 1481371 1356191 27 Locked QAM256 39 201000000 Hz -3.1 dBmV 44.7 dB 64652606 121776 275945 28 Locked QAM256 40 207000000 Hz -3.2 dBmV 43.3 dB 79938129 178392 504176 29 Locked QAM256 41 213000000 Hz -2.9 dBmV 40.0 dB 74499092 135016 319912 30 Locked QAM256 42 219000000 Hz -3.1 dBmV 45.0 dB 141626626 126901 333968 31 Locked QAM256 43 225000000 Hz -3.2 dBmV 44.9 dB 147492153 138828 316362 32 Locked QAM256 45 237000000 Hz -3.4 dBmV 44.8 dB 112051033 92936 155391

Upstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 1 16900000 Hz 43.5 dBmV 2 Locked ATDMA 2 23500000 Hz 44.3 dBmV 3 Locked ATDMA 3 29900000 Hz 44.3 dBmV 4 Locked ATDMA 4 36300000 Hz 44.8 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 300000000 Hz -6.6 dBmV 40.8 dB 296 ~ 7895 1043281678 213193654 318797 2 Locked 0, 1, 2, 3 160 918000000 Hz -15.7 dBmV 31.3 dB 1108 ~ 2987 25611780 13734826 8122335

Upstream OFDMA Channels

Channel Lock Status Modulation / Profile ID Channel ID Frequency Power 1 Locked 3, 4, 9, 10, 11, 12, 13 6 36800000 Hz 40.3 dBmV 2 Not Locked 3, 4, 9, 10, 11, 12, 13 0 0 Hz 0.0 dBmV

Current System Time: Tue May 07 19:17:47 2024

System Up Time: 2:03:09

[plemans]

The levels are also all over the place. They should be within 3.5dbmv of each other. 

Something is squirrelly with the line. 

[Larry2024]

Thank you all for the reply.  Cox tech came out this morning, he said the cable from the outside to the house needs to be replaced (he measured and said there is a 90% power drop). 

He said to take care of this first and if issue still occur afterward than he can add a new cable from my house to where the modem is located.

Will report back and share the new connection status once the cable is replaced. 

[FURRYe38]

That should help as well the the correctables and un-correctables as those should be zeros across the board. 

Also have the tech check the modems events logs. 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.

[Kitsap]

---

@Larry2024 wrote:

Thank you all for the reply.  Cox tech came out this morning, he said the cable from the outside to the house needs to be replaced (he measured and said there is a 90% power drop). 

He said to take care of this first and if issue still occur afterward than he can add a new cable from my house to where the modem is located.

Will report back and share the new connection status once the cable is replaced. 

---

Sounds like a worthwhile tech visit.  If your internal wiring, splitters, and etc. are more than a half dozen years old, it would be worthwhile to push to have that also replaced.

[Larry2024]

Cox said it will take up to 12 weeks to replace the outside line (need city permit) but funny thing happened yesterday, ATT Fiber crew outside digging holes to install fiber cables and they severed my Cox line.  Spent a few hours tried to reconnect the cables but the hack job failed so today they replaced the outside line.  Here is the new connection status:

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 237000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enable BPI+ IP Provisioning Mode Honor MDD IPv4 only

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 45 237000000 Hz 7.9 dBmV 45.5 dB 407147168 0 0 2 Locked QAM256 1 735000000 Hz 5.8 dBmV 43.0 dB 405955455 0 0 3 Locked QAM256 2 741000000 Hz 6.2 dBmV 43.1 dB 405957909 0 0 4 Locked QAM256 3 747000000 Hz 5.5 dBmV 43.2 dB 405962269 0 0 5 Locked QAM256 4 753000000 Hz 5.9 dBmV 43.4 dB 405967522 0 0 6 Locked QAM256 5 759000000 Hz 6.1 dBmV 42.6 dB 405970697 0 0 7 Locked QAM256 6 765000000 Hz 5.5 dBmV 42.8 dB 405974568 0 0 8 Locked QAM256 7 771000000 Hz 6.1 dBmV 43.5 dB 405978494 0 0 9 Locked QAM256 8 777000000 Hz 5.6 dBmV 43.1 dB 405982016 0 0 10 Locked QAM256 9 783000000 Hz 5.3 dBmV 43.1 dB 405985763 0 0 11 Locked QAM256 10 789000000 Hz 5.8 dBmV 43.4 dB 405989383 0 0 12 Locked QAM256 11 795000000 Hz 5.0 dBmV 43.0 dB 405993444 0 0 13 Locked QAM256 12 801000000 Hz 5.2 dBmV 43.1 dB 405997121 0 0 14 Locked QAM256 13 807000000 Hz 5.4 dBmV 43.4 dB 406000515 0 0 15 Locked QAM256 14 813000000 Hz 4.6 dBmV 42.9 dB 406003992 0 0 16 Locked QAM256 15 819000000 Hz 5.0 dBmV 43.1 dB 406009090 0 0 17 Locked QAM256 16 825000000 Hz 4.4 dBmV 42.8 dB 406012238 0 0 18 Locked QAM256 17 831000000 Hz 3.8 dBmV 42.3 dB 406015861 0 0 19 Locked QAM256 18 837000000 Hz 4.5 dBmV 42.8 dB 406019314 0 0 20 Locked QAM256 19 843000000 Hz 3.8 dBmV 42.4 dB 406023755 0 0 21 Locked QAM256 20 849000000 Hz 3.6 dBmV 42.2 dB 406026816 0 0 22 Locked QAM256 21 855000000 Hz 4.2 dBmV 42.6 dB 406030843 0 0 23 Locked QAM256 22 861000000 Hz 3.5 dBmV 42.2 dB 406034184 0 0 24 Locked QAM256 23 867000000 Hz 3.6 dBmV 42.3 dB 406038450 0 0 25 Locked QAM256 24 873000000 Hz 3.6 dBmV 42.1 dB 406041580 0 0 26 Locked QAM256 25 117000000 Hz 7.8 dBmV 44.5 dB 406045933 0 0 27 Locked QAM256 26 123000000 Hz 7.9 dBmV 44.6 dB 406049785 0 0 28 Locked QAM256 27 129000000 Hz 8.1 dBmV 44.9 dB 406053601 25 0 29 Locked QAM256 28 135000000 Hz 7.9 dBmV 45.0 dB 406057292 1 0 30 Locked QAM256 29 141000000 Hz 7.8 dBmV 45.3 dB 406060707 0 0 31 Locked QAM256 37 189000000 Hz 7.9 dBmV 45.4 dB 406058719 0 0 32 Locked QAM256 40 207000000 Hz 8.0 dBmV 45.5 dB 406059741 0 0

Upstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 1 16900000 Hz 37.3 dBmV 2 Locked ATDMA 2 23500000 Hz 37.8 dBmV 3 Locked ATDMA 3 29900000 Hz 37.5 dBmV 4 Locked ATDMA 4 36300000 Hz 38.0 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 300000000 Hz 7.3 dBmV 43.3 dB 296 ~ 7895 1623753096 32953507 0 2 Locked 0, 1, 2, 3 160 918000000 Hz 3.4 dBmV 40.0 dB 1108 ~ 2987 186671750 57723114 0

Upstream OFDMA Channels

Channel Lock Status Modulation / Profile ID Channel ID Frequency Power 1 Locked 3, 4, 9, 10, 11, 12, 13 6 36800000 Hz 32.3 dBmV 2 Not Locked 3, 4, 9, 10, 11, 12, 13 0 0 Hz 0.0 dBmV

Current System Time: Thu May 23 13:41:58 2024

System Up Time: 2:29:43

[FURRYe38]

Seems still a bit all over the place in power levels. Some channels are a bit too high. Something you can try get a -6Dbm coax line attenuator in put behind the modem and see if this gets the power down for those channes. 

Correctables and Un-currectables are way better though. 

[Larry2024]

Thank you FURRYe38, just ordered one from Amazon, will report back when in a couple of days.  

I really appreciate everyone's help! 

[FURRYe38]

👍

[plemans]

Probably don't have the attenuator yet but seems better if a bit all over. 

Is it any more stable? If its stable, I'd leave it without the attenuator.

Is this directly connected to the modem? meaning the outside line comes into the house and goes directly to the modem? 

[Larry2024]

I see the correctable and uncorrectable codewords for the 8 channels that are above
7 dBmV starting to build up (not a lot, fewer than one hundred) while all other channels are at 0 after 20 hours up time.  Connection seems stable and there are no warning or critical events logged.

Yes, it is a direct connection from the outside to the modem.  The cable inside is 24 yrs old and there is one female to female connector to replace a splitter that is no longer needed.

[plemans]

A few errors aren't a big deal but if its building to fast, its indicative of something needing replacing. 

Any chance you can put the modem right where that female-female connection is? Every connection adds a point of failure/errors. If that clears things up, it could be a bad connector or even ends on the cable. 

[Larry2024]

Unfortunately the female to female connection is up in the attic, there is no outlet and gets very hot up there (Phoenix, AZ).

[plemans]

---

@Larry2024 wrote:

Unfortunately the female to female connection is up in the attic, there is no outlet and gets very hot up there (Phoenix, AZ).

---

Thats does make it a bit more challenging 🙂

If its more stable and not having any drops, I'd just sit on it. You can run higher power levels but they can have instabilities if its to high. If its working follow the old golden principle of "don't fix what isn't broken". 

[Larry2024]

Thanks plemans!  I will run the current setup until the 6db attenuator gets here tomorrow.  Take a snapshot of the connection status.  Put the attenuator in and let it runs the same duration, take another snapshot and post results here for all the experts to review.

[Kitsap]

It is good practice to reboot the modem after you install the attenuator.

[Larry2024]

Yes, I will do that, thanks for the suggestion.

[Larry2024]

Hi all, I am back with another set of connection status.  This is from yet another new outside line, put in by Cox today (first time, AT&T cut my line while putting down fiber cable on 5/23).  This is without any attenuator (I do have a 6db and a 3db).  Should I give the 6db attenuator a try to bring down the power level?  Thanks...

[FURRYe38]

Yes.

Good on the correctables and un-correctables. 

Hows the event log look? 

[Larry2024]

Only Notice, there is no warning or critical...

[FURRYe38]

👍

[Larry2024]

Up for 19 hours and all the channels with above 7 dBmv started to accumulate correctables and un-correctables, with notice events only.  I just added the 3db attenuator and will let it run for a day to see if it is any better.  If not I will put the 6db on.  This is the connection status with the 3db.  Thanks!

[FURRYe38 · Accepted solution]

Looks good. Some channels are a bit far in power between the channels however if it's working. Let it run.