CM1100 Modem Not All Channels Active "Partial Service" (COX) Gig Service

[RogueRobot]

Modem: Nighthawk CM1100

Router: Nighthawk RAX80

Hi,

I have Cox gigbit service but I only get around 630mbps max (sometimes 590mbps). I logged into my CM1100 modem and it says that the Downstream Bonded Channel (Partial Service) - only channels locked are 1 - 20 (out of 32), and the rest of the channels are unlocked at 0 values. On the Uploadstream - Channels 1 - 5 (out of 😎 are the only ones locked. Detailed log below.

I called called Cox Communications and they said that "everything is fine on our end", and that it must be a defective modem but not on their end. Any ideas???

Starting Frequency

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<tabindex=-1>Startup Procedure</tabindex=-1>

Procedure	Status	Comment
Acquire Downstream Channel	957000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv4 only

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<tabindex=-1>Downstream Bonded Channels (Partial Service)</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	30	957000000 Hz	16.2 dBmV	41.1 dB	190805348	12	0
2	Locked	QAM256	1	783000000 Hz	12.5 dBmV	40.2 dB	188844156	450	0
3	Locked	QAM256	2	789000000 Hz	12.7 dBmV	40.3 dB	188847544	502	0
4	Locked	QAM256	3	795000000 Hz	12.6 dBmV	40.2 dB	188851159	438	0
5	Locked	QAM256	4	801000000 Hz	12.7 dBmV	40.3 dB	188855523	454	0
6	Locked	QAM256	9	831000000 Hz	13.3 dBmV	40.4 dB	188859281	475	0
7	Locked	QAM256	10	837000000 Hz	13.6 dBmV	40.5 dB	188863165	430	0
8	Locked	QAM256	11	843000000 Hz	14.1 dBmV	40.9 dB	188868010	281	0
9	Locked	QAM256	12	849000000 Hz	14.2 dBmV	40.7 dB	188872380	298	0
10	Locked	QAM256	17	879000000 Hz	15.5 dBmV	41.0 dB	188876375	207	0
11	Locked	QAM256	18	885000000 Hz	16.0 dBmV	41.1 dB	188879973	130	0
12	Locked	QAM256	19	891000000 Hz	16.1 dBmV	40.9 dB	188883908	128	0
13	Locked	QAM256	20	897000000 Hz	16.6 dBmV	41.3 dB	188887960	83	0
14	Locked	QAM256	21	903000000 Hz	16.9 dBmV	41.5 dB	188891762	66	0
15	Locked	QAM256	22	909000000 Hz	16.6 dBmV	41.1 dB	188895231	99	0
16	Locked	QAM256	25	927000000 Hz	17.0 dBmV	41.3 dB	188899048	50	0
17	Locked	QAM256	26	933000000 Hz	16.8 dBmV	41.4 dB	188902918	34	0
18	Locked	QAM256	27	939000000 Hz	16.8 dBmV	41.4 dB	188907079	34	0
19	Locked	QAM256	28	945000000 Hz	16.6 dBmV	41.2 dB	188910266	25	0
20	Locked	QAM256	29	951000000 Hz	16.4 dBmV	41.3 dB	188912406	21	0
21	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
22	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
23	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
24	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
25	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
26	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
27	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
28	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
29	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
30	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
31	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

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<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	19400000 Hz	40.0 dBmV
2	Locked	ATDMA	2	25800000 Hz	40.3 dBmV
3	Locked	ATDMA	3	32200000 Hz	40.0 dBmV
4	Locked	ATDMA	4	38600000 Hz	41.0 dBmV
5	Locked	ATDMA	6	14600000 Hz	39.8 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

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<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, 255	159	300000000 Hz	-39.4 dBmV	0.0 dB	0 ~ 4095	0	0	0
2	Not Locked	0, 255	0	0 Hz	-39.2 dBmV	0.0 dB	0 ~ 4095	0	0	0

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<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

[RogueRobot · Accepted solution]

So here is an update and solution.
After calling several times to convince my cable company to make a house call, they finally did. It turns out the cabling in my house was fine. The problem was that they had a "channel filter" device on their outside cable line. It took a few weeks for them to come back with a bucket lift so the they could reach the top of the near by utility pole to remove it. The tech told me they had installed those channel filters a few years back so they can block people from "stealing" or accessing and viewing cable channels from internet-only cable subscribers. But now with Gigbit internet service those same channel filters also block modem channels making internet signals unstable and slow. When I log in to my modem, it now shows it firing on all cylinders (channels). I'm a happy camper. Thanks you all.

[FURRYe38]

Have the ISP check the signal and line quality UP to the modem. 
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. 
Be sure to power OFF the modem for 1 minute them back ON.

[plemans]

Another thing to check is your downstream signal is kind of high powered. Ideal is -7dbmv to +7dbmv. You're at 16.9dbmv. 

Usually I recommend removing splitters but sometimes it can actually help if you have a good quality splitter to drop your signal a bit. 

Or using a signal attenuator. 

If you get it into a decent range, then reboot the modem and see what locks. They don't all have to lock provided you get the full speed you pay for. If you're not getting the full speed after getting your signal corrected, I'd follow what @FURRYe38 recommends and have the isp check the line. 

[RogueRobot]

Thanks guys. I will be trying all suggestions. By the way, I did see that there is a cylindrical extension type adapter when I checked the cable outside, maybe that might help if I replace it. Also, I was trying if the cable is the new type of high bandwidth cable but it doesn't have writing on it, its only white. The house is older so I wouldn't be surprised if even the cable running from their box down the street to our house was older. Now to convince them to make a house call.

Thanks again.

[FURRYe38]

Let us know how it goes. Ya time for new updated coax cabling. 

[RogueRobot · Accepted solution]

So here is an update and solution.
After calling several times to convince my cable company to make a house call, they finally did. It turns out the cabling in my house was fine. The problem was that they had a "channel filter" device on their outside cable line. It took a few weeks for them to come back with a bucket lift so the they could reach the top of the near by utility pole to remove it. The tech told me they had installed those channel filters a few years back so they can block people from "stealing" or accessing and viewing cable channels from internet-only cable subscribers. But now with Gigbit internet service those same channel filters also block modem channels making internet signals unstable and slow. When I log in to my modem, it now shows it firing on all cylinders (channels). I'm a happy camper. Thanks you all.

[plemans]

Glad to hear you got it fixed!

[RichardDM]

How do I get all Downstream Bonded Channels to be locked. I have one unlocked (#32). Comcast says they can't do it, and Netgear says they can't lock it either. Can I do it myself.  I'm not much of a tech person, but Netgear customer support recommended I get it locked so I don't loose connectivity. Thanks for your ideas.

[FURRYe38]

Sometimes the last channel 32, won't be lock in. 

Depends on what ISP supports and signal on the coax line. Have the ISP check the signal and line quality UP to the modem. 
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. 
Be sure to power OFF the modem for 1 minute them back ON.

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@RichardDM wrote:

How do I get all Downstream Bonded Channels to be locked. I have one unlocked (#32). Comcast says they can't do it, and Netgear says they can't lock it either. Can I do it myself.  I'm not much of a tech person, but Netgear customer support recommended I get it locked so I don't loose connectivity. Thanks for your ideas.

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[vkdelta]

In most areas Comcast has deployed 31 SC-QAM + 1 OFDM and in some areas it is 32 SC-QAM +1 OFDM.

you cannot make it 32 if they have not deployed those channels in your area.

32 is not that common from what I saw

[RichardDM]

Thanks everyone for your insights. It sounds like my one unlocked channel is not that much of an issue.  I will update my cable to RG6 cable, and make sure no splitters.

By doing those corrections, does that have any effect on intermittant service? Or does Comcast/Netgear need to do something to lock all channels?