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CM Status issues and spotty connectivity

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Frequent Visitor

CM Status issues and spotty connectivity

I am reading up on these issues and hope to get help before I attempt to call for support.  No splitters in-line within our house.  The cable connects directly to the line in the house that the modem is located on, it is connected via an adapter that was installed by an Xfinity tech a few years ago.  Two kids at home doing virtual learning and one parent working from home.  This morning our modem event log has constant CM Status error messages on Ch. 48.  Code is either 16 or 24, almost every minute.

"CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=c8:63:fc:a2:c6:35;CMTS-MAC=00:01:5c:73:b4:56;CM-QOS=1.1;CM-VER=3.1;"
 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=c8:63:fc:a2:c6:35;CMTS-MAC=00:01:5c:73:b4:56;CM-QOS=1.1;CM-VER=3.1;"

Channel IDLock StatusModulationFrequencyPowerSNR/MERCorrectedUncorrectables
20LockedQAM256525000000 Hz5.5 dBmV38.6 dB413363
8LockedQAM256447000000 Hz4.7 dBmV38.6 dB539204
9LockedQAM256453000000 Hz5.0 dBmV38.5 dB510172
10LockedQAM256459000000 Hz5.3 dBmV38.7 dB479185
11LockedQAM256465000000 Hz5.5 dBmV38.7 dB533159
12LockedQAM256471000000 Hz5.3 dBmV38.6 dB453173
13LockedQAM256477000000 Hz5.1 dBmV38.6 dB461147
14LockedQAM256483000000 Hz4.9 dBmV38.4 dB491155
15LockedQAM256489000000 Hz4.9 dBmV38.4 dB459149
16LockedQAM256495000000 Hz5.1 dBmV38.5 dB450199
17LockedQAM256507000000 Hz5.2 dBmV38.7 dB518153
18LockedQAM256513000000 Hz5.1 dBmV38.7 dB473184
19LockedQAM256519000000 Hz5.2 dBmV38.6 dB381307
21LockedQAM256531000000 Hz5.7 dBmV38.7 dB457321
22LockedQAM256537000000 Hz5.6 dBmV38.7 dB425500
23LockedQAM256543000000 Hz5.0 dBmV38.6 dB495468
24LockedQAM256549000000 Hz5.1 dBmV38.5 dB537590
25LockedQAM256555000000 Hz5.4 dBmV38.7 dB641815
26LockedQAM256561000000 Hz5.4 dBmV38.5 dB6801009
27LockedQAM256567000000 Hz4.8 dBmV38.4 dB6461133
28LockedQAM256573000000 Hz4.4 dBmV38.3 dB6441273
29LockedQAM256579000000 Hz4.2 dBmV38.3 dB7301517
30LockedQAM256585000000 Hz4.3 dBmV38.2 dB7261599
31LockedQAM256591000000 Hz4.0 dBmV38.0 dB8861783
32LockedQAM256597000000 Hz3.6 dBmV37.9 dB10092129
33LockedQAM256603000000 Hz3.0 dBmV37.7 dB12372487
34LockedQAM256609000000 Hz3.0 dBmV37.6 dB11052774
35LockedQAM256615000000 Hz3.4 dBmV37.7 dB12892997
36LockedQAM256621000000 Hz3.2 dBmV37.7 dB14153350
37LockedQAM256627000000 Hz2.3 dBmV37.3 dB16493801
38LockedQAM256633000000 Hz1.9 dBmV37.1 dB18074156
48LockedOther850000000 Hz3.9 dBmV32.8 dB514030658186524

 

ChannelChannel IDLock StatusUS Channel TypeFrequencyWidthPower
12LockedSC-QAM Upstream23700000 Hz6400000 Hz41.0 dBmV
21LockedSC-QAM Upstream17300000 Hz6400000 Hz41.0 dBmV
33LockedSC-QAM Upstream30300000 Hz6400000 Hz41.0 dBmV
44LockedSC-QAM Upstream36700000 Hz6400000 Hz41.0 dBmV

 

I see that something is wrong with Ch 48.  I just power cycled my modem and router, and removed the coax cable from the modem and re-attached, checking the center pin for corrosion.   Do I need tech support yet?  Arris SB8200 modem and Orbi 4200AX mesh wifi.  

Thanks!

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Frequent Visitor

Re: CM Status issues and spotty connectivity

I broke down and tried tech support via chat.  The person helping me said they can see that my signal has been unstable since 10/1.  He provisioned my modem and we restarted everything again.  He said the signal appears stable now, but my modem is still showing the same issues.  What do I believe?  

20LockedQAM256525000000 Hz-4.2 dBmV38.3 dB3181148
8LockedQAM256447000000 Hz-4.7 dBmV38.1 dB3831586
9LockedQAM256453000000 Hz-4.6 dBmV38.1 dB3751590
10LockedQAM256459000000 Hz-4.1 dBmV38.3 dB4071561
11LockedQAM256465000000 Hz-4.0 dBmV38.3 dB3771574
12LockedQAM256471000000 Hz-4.4 dBmV38.2 dB3671587
13LockedQAM256477000000 Hz-4.5 dBmV38.1 dB2821127
14LockedQAM256483000000 Hz-4.6 dBmV38.0 dB3881643
15LockedQAM256489000000 Hz-4.7 dBmV38.0 dB3961583
16LockedQAM256495000000 Hz-4.6 dBmV38.1 dB3741602
17LockedQAM256507000000 Hz-4.5 dBmV38.3 dB3771587
18LockedQAM256513000000 Hz-4.5 dBmV38.2 dB3941616
19LockedQAM256519000000 Hz-4.5 dBmV38.1 dB4281636
21LockedQAM256531000000 Hz-4.0 dBmV38.4 dB00
22LockedQAM256537000000 Hz-4.0 dBmV38.5 dB2341023
23LockedQAM256543000000 Hz-4.4 dBmV38.3 dB12192005
24LockedQAM256549000000 Hz-4.5 dBmV38.3 dB4141666
25LockedQAM256555000000 Hz-4.0 dBmV38.3 dB3971638
26LockedQAM256561000000 Hz-4.0 dBmV38.3 dB3791676
27LockedQAM256567000000 Hz-4.5 dBmV38.1 dB3901689
28LockedQAM256573000000 Hz-4.8 dBmV38.0 dB3911678
29LockedQAM256579000000 Hz-4.8 dBmV38.0 dB4031666
30LockedQAM256585000000 Hz-4.6 dBmV38.0 dB3811676
31LockedQAM256591000000 Hz-4.7 dBmV37.8 dB4001674
32LockedQAM256597000000 Hz-5.0 dBmV37.8 dB2281035
33LockedQAM256603000000 Hz-5.4 dBmV37.7 dB5631739
34LockedQAM256609000000 Hz-5.6 dBmV37.5 dB4311634
35LockedQAM256615000000 Hz-5.0 dBmV37.8 dB4331633
36LockedQAM256621000000 Hz-4.9 dBmV37.8 dB3751664
37LockedQAM256627000000 Hz-5.8 dBmV37.4 dB4231642
38LockedQAM256633000000 Hz-6.4 dBmV37.1 dB3971678
48LockedOther850000000 Hz-11.5 dBmV32.2 dB188992184

 

4023

 

 

12LockedSC-QAM Upstream23700000 Hz6400000 Hz48.0 dBmV
21LockedSC-QAM Upstream17300000 Hz6400000 Hz48.0 dBmV
33LockedSC-QAM Upstream30300000 Hz6400000 Hz49.0 dBmV
44LockedSC-QAM Upstream36700000 Hz6400000 Hz49.0 dBmV

 

Same two events all day today.

10/07/2020 15:17740101006"CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=c8:63:fc:a2:c6:35;CMTS-MAC=00:01:5c:73:b4:56;CM-QOS=1.1;CM-VER=3.1;"
10/07/2020 15:16740101006"CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=c8:63:fc:a2:c6:35;CMTS-MAC=00:01:5c:73:b4:56;CM-QOS=1.1;CM-VER=3.1;"

 

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Frequent Visitor

Re: CM Status issues and spotty connectivity

My previous post showing the modem status and event logs was taken with a MOCA splitter inline.  That may be why ch. 48 had -11dBmV.  Still getting the same events today.  I had to use my phone as a hotspot to get work done today.  The signal was very unstable.

20LockedQAM256525000000 Hz3.7 dBmV38.6 dB00
8LockedQAM256447000000 Hz3.4 dBmV38.5 dB00
9LockedQAM256453000000 Hz3.4 dBmV38.4 dB00
10LockedQAM256459000000 Hz3.8 dBmV38.6 dB00
11LockedQAM256465000000 Hz4.0 dBmV38.6 dB00
12LockedQAM256471000000 Hz3.7 dBmV38.5 dB00
13LockedQAM256477000000 Hz3.4 dBmV38.4 dB00
14LockedQAM256483000000 Hz3.1 dBmV38.3 dB00
15LockedQAM256489000000 Hz3.1 dBmV38.3 dB00
16LockedQAM256495000000 Hz3.4 dBmV38.4 dB00
17LockedQAM256507000000 Hz3.2 dBmV38.5 dB00
18LockedQAM256513000000 Hz3.2 dBmV38.6 dB00
19LockedQAM256519000000 Hz3.3 dBmV38.5 dB00
21LockedQAM256531000000 Hz3.6 dBmV38.5 dB00
22LockedQAM256537000000 Hz3.7 dBmV38.6 dB00
23LockedQAM256543000000 Hz3.3 dBmV38.6 dB00
24LockedQAM256549000000 Hz3.3 dBmV38.6 dB00
25LockedQAM256555000000 Hz3.6 dBmV38.6 dB00
26LockedQAM256561000000 Hz3.5 dBmV38.6 dB00
27LockedQAM256567000000 Hz3.0 dBmV38.4 dB00
28LockedQAM256573000000 Hz2.8 dBmV38.3 dB00
29LockedQAM256579000000 Hz2.8 dBmV38.3 dB250
30LockedQAM256585000000 Hz2.9 dBmV38.3 dB1716
31LockedQAM256591000000 Hz2.5 dBmV38.1 dB311
32LockedQAM256597000000 Hz2.3 dBmV38.0 dB293
33LockedQAM256603000000 Hz2.0 dBmV37.9 dB450
34LockedQAM256609000000 Hz2.1 dBmV38.0 dB5131
35LockedQAM256615000000 Hz2.5 dBmV38.0 dB8935
36LockedQAM256621000000 Hz2.4 dBmV38.0 dB6077
37LockedQAM256627000000 Hz1.8 dBmV37.7 dB4483
38LockedQAM256633000000 Hz1.5 dBmV37.6 dB109172
48LockedOther850000000 Hz-0.7 dBmV33.5 dB129997892695206

 

12LockedSC-QAM Upstream23700000 Hz6400000 Hz41.0 dBmV
21LockedSC-QAM Upstream17300000 Hz6400000 Hz41.0 dBmV
33LockedSC-QAM Upstream30300000 Hz6400000 Hz41.0 dBmV
44LockedSC-QAM Upstream36700000 Hz6400000 Hz41.0 dBmV

 

Online search tells me my modem is having trouble staying bonded.  The code 16 and 24 events just keep alternating.  I am currently waiting for the technician to show up, but a representative from their advanced network support called me to tell me that the signal appears fine on their end, and asked if my internet is working.  I said no, and he asked if I was measuring the performance over wireless or connected directly to the modem.  I told him our modem is still reporting issues and that our connectivity has been really bad.  He gave up really quickly and said the tech should be here soon.  

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Contributor

Re: CM Status issues and spotty connectivity

Weird how your ch 48 is locked but listed as other.  Tech should be able to help and since you have your own equip that's pretty much your only option.  Seems like some sort of wiring issue somewhere or that MoCA is bad.

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Expert

Re: CM Status issues and spotty connectivity


@xsandos wrote:

Weird how your ch 48 is locked but listed as other.  Tech should be able to help and since you have your own equip that's pretty much your only option.  Seems like some sort of wiring issue somewhere or that MoCA is bad.


Channel 48 / other (no matter what the local system channel label number is) it's arbitrary on any local system.  It is the DOCSIS 3.1 / OFDM downstream channel for their gigabit speed tier and it is a known firmware issue that some makes and models of modems's measuring mechanisms incorrectly read the signal stats and the bit errors.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Frequent Visitor

Re: CM Status issues and spotty connectivity

Thanks for the responses.  Regardless of whether or not I have the MOCA splitter attached, ch 48 is always out of whack, it just went lower in power with the splitter.  EG you are saying ch 48 isn't something I should be concerned about, then I'm good with that.  The error logs still have repeating 24/16 codes every minute or two.  All of that may be benign, but our service has been terrible lately, and the last two days have been the worst.

The visiting technician checked our outside connection first.  He replaced the MOCA poe filter that is between the source coax and our home. I did not know they used these (it makes perfect sense now though) so I guess I don't need to install one inside my home when I set up our MOCA.  Checking the signal strength made him go and check the node a few houses down.  He said the box in the ground was filled with water, the connection adapter to our line was swollen, and the ends of the cables were hard from the repetitive heat cycling and water intrusion.  The connection piece was replaced and some cable ends cut and recapped with new adapters.  He monitored the signal strength and noticed enough of a drop to suggest that might be our issue.  He came inside and checked our connections, but nothing exciting.  He put in a request to have the underground line replaced due to the signal drop he noticed.  Not sure what we can do about the water, maybe talk to our neighbors.  

School and work is now in session here, and it seems to be behaving so far.  The new underground cable should be dropped today or early next week.  Hopefully that will restore everything back to normal.

I was going to install our old modem to see if we get the same issues.  The new one is only 2 months old, and of course out of the return period, but I'll bite the bullet and get another one if it helps.  Can't have the wife telling me the internet is not working.

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Frequent Visitor

Re: CM Status issues and spotty connectivity

New underground cable was replaced yesterday, and now my event log is completely empty.  Hopefully it stays that way for a long time.