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Thursday, March 21st, 2024 5:28 PM

Netgear cm3000 modem downstream blinking/not channel bonding/not getting DOCSIS 3.1?

Hi.  First let me be clear - my internet overall is behaving quite well.  I have Gigabit Extra and while I never get to 1.2gbps, my down speeds are 300-700mbps WiFi and 700-950mbps Ethernet.  This is also with no outages.  So I'm not complaining...   I just have a few weird technical issues I would like resolved or at least some answers.

The issues I've had for a while is the downstream connection is showing that it's having trouble bonding along with high uncorrectables.  Don't get me started on the event logs.

I previously had a Motorola mb8600 and it was the same issue there as well.  I just recently upgraded to a Netgear cm3000 and it's still showing a blinking downstream LED or what it calls 'partial service mode'.  It's also showing unlocked OFDMA downstream and upstream channels which tells me it's in DOCSIS 3.0 & and not 3.1.

A tech was just out here today and put in all new coax cables outside and inside directly to modem, checked all the wiring, no splitters etc. and assured my everything he saw on his end was in good standing.  He had no answers for the issues I was describing to him and that he need a supervisor to call me.  I would just like to make sure things are working they way they should.

Here is what Netgear is showing me:

Cable Diagnostic

Status: Poor

Action:
[Partial Service]
If the Partial Service mode does not go away within a few hours (Click the Refresh button after each step):
1) Make sure the coaxial cable is tightly connected.
2) Remove any unnecessary splitters.
3) Replace any required ones.
4) Contact your service provider for troubleshooting help.

CM Status: Good

Downstream Status: Poor

    Partial Service: Poor
    Cable modem is in partial service mode. 

    Downstream Power Level: Good

    Downstream SNR Level: Good

Upstream Status: Good

    Upstream Power Level: Good

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 525000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD IPv6 only
 
Downstream Bonded Channels (Partial Service)
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 21 525000000 Hz 5.1 dBmV 41.2 dB 0 0
2 Locked QAM256 13 477000000 Hz 5.6 dBmV 42.2 dB 0 0
3 Locked QAM256 14 483000000 Hz 5.7 dBmV 42.3 dB 0 0
4 Locked QAM256 15 489000000 Hz 5.8 dBmV 42.3 dB 0 0
5 Locked QAM256 16 495000000 Hz 5.7 dBmV 42.3 dB 0 0
6 Locked QAM256 17 501000000 Hz 5.7 dBmV 42.3 dB 0 0
7 Locked QAM256 18 507000000 Hz 5.6 dBmV 42.2 dB 0 0
8 Locked QAM256 19 513000000 Hz 5.5 dBmV 42.2 dB 0 0
9 Locked QAM256 20 519000000 Hz 5.5 dBmV 40.6 dB 0 0
10 Locked QAM256 22 531000000 Hz 5.0 dBmV 41.9 dB 0 0
11 Locked QAM256 23 537000000 Hz 4.8 dBmV 41.9 dB 0 0
12 Locked QAM256 24 543000000 Hz 4.7 dBmV 41.9 dB 0 0
13 Locked QAM256 25 549000000 Hz 4.7 dBmV 41.9 dB 0 0
14 Locked QAM256 26 555000000 Hz 4.5 dBmV 41.8 dB 0 0
15 Locked QAM256 27 561000000 Hz 4.7 dBmV 41.3 dB 0 0
16 Locked QAM256 28 567000000 Hz 4.7 dBmV 40.6 dB 0 0
17 Locked QAM256 29 573000000 Hz 4.6 dBmV 40.7 dB 0 0
18 Locked QAM256 30 579000000 Hz 4.8 dBmV 41.1 dB 0 0
19 Locked QAM256 31 585000000 Hz 4.6 dBmV 41.4 dB 0 0
20 Locked QAM256 32 591000000 Hz 4.8 dBmV 41.5 dB 0 0
21 Locked QAM256 33 597000000 Hz 4.9 dBmV 41.5 dB 0 0
22 Locked QAM256 34 603000000 Hz 4.7 dBmV 41.4 dB 0 0
23 Locked QAM256 35 609000000 Hz 4.7 dBmV 41.4 dB 0 0
24 Locked QAM256 36 615000000 Hz 4.6 dBmV 41.2 dB 0 0
25 Locked QAM256 37 621000000 Hz 4.8 dBmV 41.3 dB 0 0
26 Locked QAM256 38 627000000 Hz 4.6 dBmV 40.9 dB 17227 11816
27 Locked QAM256 39 633000000 Hz 4.4 dBmV 41.0 dB 7562 509
28 Locked QAM256 40 639000000 Hz 4.2 dBmV 41.0 dB 4393 135
29 Locked QAM256 41 645000000 Hz 4.3 dBmV 41.0 dB 0 0
30 Locked QAM256 42 651000000 Hz 4.2 dBmV 41.1 dB 0 0
31 Locked QAM256 43 657000000 Hz 4.1 dBmV 40.9 dB 0 0
32 Locked QAM256 44 663000000 Hz 4.0 dBmV 40.9 dB 0 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 2560 Ksym/sec 10400000 Hz 40.5 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 16400000 Hz 39.5 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 39.0 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 29200000 Hz 39.0 dBmV
5 Locked ATDMA 5 5120 Ksym/sec 35600000 Hz 39.5 dBmV
6 Locked ATDMA 6 2560 Ksym/sec 40400000 Hz 39.5 dBmV
7 Not Locked Unknown 0 0 0 0.0 dBmV
8 Not Locked Unknown 0 0 0 0.0 dBmV
 
Downstream OFDM Channels
Channel Lock Status Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier
Number Range
Unerrored
Codewords
Correctable
Codewords
Uncorrectable
Codewords
1 Not Locked 0 ,1 ,2 ,3 159 690000000 Hz 4.88 dBmV 36.5 dB 1126 ~ 2969 32824865 32048636 772071
2 Not Locked 0 0 0 Hz 0 dBmV 0 dB 0 ~ 4095 0 0 0
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked 0 0 0 Hz 0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV
 

These were taken 17 minutes after a reboot.

Why can I not get fully bonded downstream?  Am I correct that I'm not receiving DOCSIS 3.1?  Why are my downstream OFDMA channels unlocked?  What more can I do... I've already asked support to make sure the right boot file and provision was sent to my modem(I was told yes). 

And now I've had a tech out who couldn't provide answers to these specific questions.  Don't get me wrong, he was great when it came to re-wiring and doing his job.  He's also having someone call me in 3-5 days.

But before that I wanted to see if someone here can hopefully provide some insight.   Thanks much in advance.

3 Messages

3 months ago

Can someone please at the very least just tell me that I'm not wrong and my downstream ODMF channel should be locked?  Especially if I'm supposed to be receiving DOCSIS 3.1 and Gigabit Extra?  

I'm also still getting partial service and a blinking downstream.  The amount of uncorrectables is now in the multi-millions on 4 channels including the ODFM 1.

I have an open Netgear support case and they are telling me Xfinity needs to re-provision the the modem and something most likely went wrong when it was originally activated. 

Any help would be greatly appreciated.

(edited)

Official Employee

 • 

721 Messages

3 months ago

Hello, kbshcb. Thank you for taking the time to create a post, you have contacted the right place for assistance in regard to the question about your locked channel. Researching I found this great forums post: https://forums.xfinity.com/conversations/your-home-network/docsis-31-modem-not-provisioned-correctly-docsis-30-qam-256-channels-vs-docsis-31-ofdm/602dae4ac5375f08cde52110. 

 

- Gig speed is delivered only via the DOCSIS 3.1 / OFDM downstream channel. If there are multiple bonded DOCSIS 3.0 channels present, it does not indicate 3.1.

 

Looking over your posted information I do see multiple locked Bonded Channels, so your equipment should be getting that Gig signal over Docsis 3.1. 

 

In regard to looking at the modem provisioning and not receiving the 1.2 Gigabit speed, I would definitley like to investigate further. When you have time, please send a direct message. 

 

To send a direct message: 

 

Click "Sign In" if necessary

 

• Click the "Direct Message" icon in the upper right - it looks like a chat bubble  

• Click the "New message" (pencil and paper) icon just to the right of Conversations

• Type "Xfinity Support" in the "To:" line - do not use the Employee's name!

• Type your message in the text area near the bottom of the window

• Press Enter to send it

To expedite your request, we ask that you please include your name, the account holder name (if different), and the service address.

 

 

3 Messages

@XfinityJustinC​ 

First, thank you for replying.  I have sent a direct message to support as you recommended.  Hopefully someone will help and get my modem re-provisioned correctly, if that's the issue.

I do agree with you that I have multiple downstream QAM bonded channels.  But The issue still remains that my Netgear modem's downstream LED is blinking, the diagnostics say I have poor/partial service, and that the fact that my downstream OFDM channel is not locked means there is an issue.

Thank you again so much and I look forward to getting some help.

Contributor

 • 

67 Messages

22 days ago

Did this ever get resolved?

Just curious because I made a similar transition from a MB8600 to CM3000 modem and have noticed upstream channels are now use ATDMA modulation instead of SC-QAM. Seems strange...

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