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Unable to connect via DOCSIS 3.1

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Unable to connect via DOCSIS 3.1

I am a new customer and have my own cable modem, which is a Netgear CM1000v2.  I paid extra for a 3.1 modem to take advantage of the latency queueing capabilities but for some reason, it's not showing the OFDM channels.  I've called support and they are oriented towards "break/fix" and based on the download/upload speeds I'm getting (150Mbps down/10Mbps up), and my signal levels, etc, they haven't been able to help me.  I'm starting to wonder if DOCSIS 3.1 is availible in my area.  I believe the fastest speed in my area is arund 200Mbps.  I'm perfectly fine with 150Mbps, but I do really want to take advantage of DOCSIS 3.1 if I can.  Or find out if it's not an option for me at this time.  And if that's the case, I will stop digging into the issue and wait for an upgrade.  I haven't been able to get that information by calling 1st level support and asking for an escalation though.

 

The Firmware Version of my modem is V6.01.06 and here are the cable modem stats.

 

Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 381000000 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 22 381000000 Hz 10.4 dBmV 42.9 dB 2790586891 0 0
2 Locked QAM256 1 453000000 Hz 10.8 dBmV 42.1 dB 2789581726 0 0
3 Locked QAM256 2 459000000 Hz 10.6 dBmV 42.0 dB 2789584496 0 0
4 Locked QAM256 3 465000000 Hz 10.5 dBmV 41.9 dB 2789589709 0 0
5 Locked QAM256 4 471000000 Hz 10.4 dBmV 42.0 dB 2789593750 0 0
6 Locked QAM256 5 477000000 Hz 10.0 dBmV 42.0 dB 2789598871 0 0
7 Locked QAM256 6 483000000 Hz 9.5 dBmV 41.9 dB 2789599952 0 0
8 Locked QAM256 7 489000000 Hz 9.4 dBmV 41.9 dB 2789604712 0 0
9 Locked QAM256 8 495000000 Hz 9.7 dBmV 42.0 dB 2789609826 0 0
10 Locked QAM256 9 501000000 Hz 9.9 dBmV 42.1 dB 2789613247 0 0
11 Locked QAM256 10 507000000 Hz 10.1 dBmV 41.9 dB 2789608574 0 0
12 Locked QAM256 11 513000000 Hz 9.9 dBmV 41.9 dB 2789613304 0 0
13 Locked QAM256 12 519000000 Hz 9.8 dBmV 41.6 dB 2789617038 0 0
14 Locked QAM256 13 525000000 Hz 9.9 dBmV 41.7 dB 2789620534 0 0
15 Locked QAM256 14 531000000 Hz 9.9 dBmV 41.6 dB 2789623156 0 0
16 Locked QAM256 15 543000000 Hz 9.9 dBmV 41.8 dB 2789627163 0 0
17 Locked QAM256 16 549000000 Hz 9.8 dBmV 41.8 dB 2789631309 0 0
18 Locked QAM256 17 351000000 Hz 10.4 dBmV 43.0 dB 2789635954 0 0
19 Locked QAM256 18 357000000 Hz 10.4 dBmV 43.3 dB 2789639375 0 0
20 Locked QAM256 19 363000000 Hz 10.4 dBmV 43.0 dB 2789642765 0 0
21 Locked QAM256 20 369000000 Hz 10.4 dBmV 42.8 dB 2789646568 0 0
22 Locked QAM256 21 375000000 Hz 10.3 dBmV 42.9 dB 2789649248 0 0
23 Locked QAM256 23 387000000 Hz 10.4 dBmV 43.0 dB 2789652767 0 0
24 Locked QAM256 24 393000000 Hz 10.5 dBmV 42.7 dB 2789658165 0 0
25 Locked QAM256 25 399000000 Hz 10.5 dBmV 42.9 dB 2789661703 0 0
26 Locked QAM256 26 405000000 Hz 10.6 dBmV 42.9 dB 2789664406 0 0
27 Locked QAM256 27 411000000 Hz 10.6 dBmV 42.8 dB 2789669503 0 0
28 Locked QAM256 28 417000000 Hz 10.6 dBmV 42.6 dB 2789671865 0 0
29 Locked QAM256 29 423000000 Hz 10.7 dBmV 42.8 dB 2789676538 0 0
30 Locked QAM256 30 429000000 Hz 10.9 dBmV 42.9 dB 2789678413 0 0
31 Locked QAM256 31 435000000 Hz 11.1 dBmV 42.8 dB 2789678809 0 0
32 Locked QAM256 32 441000000 Hz 10.9 dBmV 42.6 dB 2789679201 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 35800000 Hz 37.0 dBmV
2 Locked ATDMA 2 29400000 Hz 37.0 dBmV
3 Locked ATDMA 3 23000000 Hz 37.5 dBmV
4 Locked ATDMA 4 16600000 Hz 36.3 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

<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 Not Locked Unknown 0 0 Hz 0 dBmV 0 dB 0 ~ 0 0 0 0
2 Not Locked Unknown 0 0 Hz 0 dBmV 0 dB 0 ~ 0 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

 

 

I cleared the event logs and rebooted my modem and here's what it shows:

 

Time Priority Description
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=<masked for security>;CMTS-MAC=<Masked for security>;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=<masked for security>;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

 

Thanks for any help!

Craig

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New Poster

Re: Unable to connect via DOCSIS 3.1

Craig,

I had the same issue with another Netgear modem/router. the issue is related to a firmware update that is pushed out from the ISP (which now has to do all the firmware updates). Unplug the coax or ethernet from the ISP. Push in the factory reset button on the modem (one that you need to use a paperclip, small hole usually next to the power button). Then re-hook the cable or etherent connection. this should resync the ISP and update firmware. Even though I pressed the factory reset button, all of my setting were still there after it reintialized.

Hope this helps. I got the solution from Reddit and not Netgear or Xfinity.

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Expert

Re: Unable to connect via DOCSIS 3.1


@craigb108 wrote:

I'm starting to wonder if DOCSIS 3.1 is availible in my area.  I believe the fastest speed in my area is arund 200Mbps. 


If the Gigabit tier is available in your area, then you have DOCSIS 3.1 service. 

 

From what I can see there doesn't seem to be anything wrong with your signals otherwise. 

 

 


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

Re: Unable to connect via DOCSIS 3.1

FWIW, I don't see a DOCSIS 3.1 / OFDM downstream channel being locked on to. You need one in order to be able to get gig speed.



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
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Frequent Visitor

Re: Unable to connect via DOCSIS 3.1

I will give that a shot!  Here's firmware it's running before trying that:

 

V6.01.06

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Frequent Visitor

Re: Unable to connect via DOCSIS 3.1

They only go up to 200Mbps in my area so it's very possible that they running some legacy gear.

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Frequent Visitor

Re: Unable to connect via DOCSIS 3.1

Held the rest button for 5 plus seconds after disconnecting the Coax.  It seemed like the cable modem reset a few times but even after a good 40 minutes it came up on firmware version V6.01.06.  I know it reset because I couldn't get in at first and tried the original default password, which it took even though I had changed it.  Still no OFDM channels, so I may be stuck with 3.0 until they upgrade in my area.

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Frequent Visitor

Re: Unable to connect via DOCSIS 3.1

So I had a contact that works on the construction side because I had to have 700 feet of cable bored to my house.  I reached out to him and he let me know 3.1 is not availible in my area yet.  At least I know I can stop trying to connect to something that isn't there.  Plus, I'm ready when it does eventually roll out.  

 

So maybe this will help somebody in the same boat.  I thought maybe Comcast had made the switch to 3.1 across the board since it had been around a while, but that is not the case.  So if your area only goes to 200Mbps or so, you probably don't have the option to utilize the advanced 3.1 spec yet.