Forum Discussion

Star

Mar 28, 2019

Solved

CM1150V Upstream Channel Problem with Xfinity

I purchased a CM1150V to replace an Xfinity (Arris) XB6. The XB6 had been in place, running in bridge mode, for 2 months. It showed (4) upstream channels with good power levels, (31+OFDM) downstre...

Scott_UU
Apr 03, 2019
An Xfinity tech was out today. He found a noise block filter at the pole. No idea when or why it was installed. That was blocking the two lower frequency channels.

A noise block filter had previously been ruled out, because the Xfinity-supplied Arris XB6 was reporting all (4) channels locked. So I now question the veracity of the Arris XB6 status page. All other modems tested (CM1150V, Arris TM722G, Arris SBV3202) were unable to lock the channels with that filter in place. So I don't think the Arris XB6 was actually locking those channels either, even though it said it was.

Once the tech removed the noise block filter at the pole, the CM1150V immediately locked all (4) channels. The constant T3/T4 errors are gone as well. No problems with the CM1150V, the upstream issue was all from a previous Xfinity/Comcast tech installing that noise block filter at the tap.

Thanks to vkdelta for help and supporting information, which helped me explain/prove the problem to Xfinity so they would come fix it!

Scott_UU

Star

Apr 04, 2019

FunBucks wrote:

The upstream light is always flashing green. Never solid green like all other lights.

I am curious about this as well. When I was only getting 2 of the 4 upstream channels, the GUI said "(partial service)" above the channel list AND the upstream light was flashing to indicate "partial service". Now that I'm getting all 4 upstream channels, the "(partial service)" text is gone from the GUI -- but the upstream light is still flashing. Have rebooted and factory reset, but the LED is still flashing. Hopefully someone from Netgear can answer that for both of us.

FunBucks wrote:

Also, my router is plugged into Ethernet Port 1. Works. When I plug anything else (ie PC) into ethernet ports 2,3,4 nothing happens. I should just get direct hardwired internet to my PC? Correct? So why do the other 3 ethernet ports not work.

The CM1150V is a modem, not a gateway or router, so it has no routing capability. You'll need to connect your router to the modem, and your other devices to the router. The additional ethernet ports are for the "port aggregation" feature, which allows (if you have latest firmware, a plan with sufficient speed to need it, and a modem that supports it) a multi-gigabyte connection between the modem and the router.

vkdelta

NETGEAR Employee Retired

Apr 04, 2019

customer>>

The upstream light is always flashing green. Never solid green like all other lights. -

response>>

This is because of partial service on upstream. if you fix the coax/line/plant issues and all 4 upstreams are locked.

customer>>

Also, my router is plugged into Ethernet Port 1. Works.

When I plug anything else (ie PC) into ethernet ports 2,3,4 nothing happens. I should just get direct hardwired internet to my PC? Correct?

So why do the other 3 ethernet ports not work.

response>>

Port 2,3,4 will only work if you have Multiple IP service package for different IPs. Some ISPs offer it, not all though.

Port 1,2 will work together if you enable LAG and have LAG-capable router.

vkdelta

NETGEAR Employee Retired

Apr 04, 2019

response>>

This is because of partial service on upstream. if you fix the coax/line/plant issues and all 4 upstreams are locked then LED will be solid.

Scott_UU

Star

Apr 04, 2019

vkdelta wrote:

response>>

This is because of partial service on upstream. if you fix the coax/line/plant issues and all 4 upstreams are locked then LED will be solid.

But my upstream problem IS fixed... Channel status now shows all provisioned channels locked, and the "partial service" text is gone from the GUI. BUT THE LIGHT IS STILL FLASHING. Have tried power cycle and factory reset, US light still flashes. ????

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectables
1	Locked	QAM256	29	663000000 Hz	-2.4 dBmV	38.8 dB	0	0
2	Locked	QAM256	1	483000000 Hz	-1.5 dBmV	39.8 dB	0	0
3	Locked	QAM256	2	489000000 Hz	-1.4 dBmV	39.8 dB	0	0
4	Locked	QAM256	3	495000000 Hz	-1.4 dBmV	39.8 dB	0	0
5	Locked	QAM256	4	507000000 Hz	-1.6 dBmV	39.7 dB	0	0
6	Locked	QAM256	5	513000000 Hz	-1.8 dBmV	39.7 dB	0	0
7	Locked	QAM256	6	519000000 Hz	-1.7 dBmV	39.8 dB	0	0
8	Locked	QAM256	7	525000000 Hz	-1.7 dBmV	39.8 dB	0	0
9	Locked	QAM256	8	531000000 Hz	-1.8 dBmV	39.7 dB	0	0
10	Locked	QAM256	9	543000000 Hz	-2 dBmV	39.6 dB	0	0
11	Locked	QAM256	10	549000000 Hz	-1.9 dBmV	39.6 dB	0	0
12	Locked	QAM256	11	555000000 Hz	-1.9 dBmV	39.5 dB	0	0
13	Locked	QAM256	12	561000000 Hz	-1.7 dBmV	39.6 dB	0	0
14	Locked	QAM256	13	567000000 Hz	-1.8 dBmV	39.6 dB	0	0
15	Locked	QAM256	14	573000000 Hz	-1.9 dBmV	39.6 dB	0	0
16	Locked	QAM256	15	579000000 Hz	-1.9 dBmV	39.5 dB	0	0
17	Locked	QAM256	16	585000000 Hz	-2 dBmV	39.5 dB	0	0
18	Locked	QAM256	17	591000000 Hz	-1.9 dBmV	39.5 dB	0	0
19	Locked	QAM256	18	597000000 Hz	-2 dBmV	39.4 dB	0	0
20	Locked	QAM256	19	603000000 Hz	-2.1 dBmV	39.3 dB	0	0
21	Locked	QAM256	20	609000000 Hz	-2.3 dBmV	39.3 dB	0	0
22	Locked	QAM256	21	615000000 Hz	-2.4 dBmV	39.2 dB	0	0
23	Locked	QAM256	22	621000000 Hz	-2.4 dBmV	39.1 dB	0	0
24	Locked	QAM256	23	627000000 Hz	-2.4 dBmV	39.1 dB	0	0
25	Locked	QAM256	24	633000000 Hz	-2.3 dBmV	39 dB	0	0
26	Locked	QAM256	25	639000000 Hz	-2.5 dBmV	38.9 dB	0	0
27	Locked	QAM256	26	645000000 Hz	-2.6 dBmV	38.8 dB	0	0
28	Locked	QAM256	27	651000000 Hz	-2.5 dBmV	38.7 dB	0	0
29	Locked	QAM256	28	657000000 Hz	-2.6 dBmV	38.8 dB	0	0
30	Locked	QAM256	30	669000000 Hz	-2.6 dBmV	38.7 dB	0	0
31	Locked	QAM256	31	675000000 Hz	-2.7 dBmV	37.9 dB	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	5	5120 Ksym/sec	30100000 Hz	39.3 dBmV
2	Locked	ATDMA	6	5120 Ksym/sec	36500000 Hz	39.8 dBmV
3	Locked	ATDMA	7	5120 Ksym/sec	17300000 Hz	37.3 dBmV
4	Locked	ATDMA	8	5120 Ksym/sec	23700000 Hz	38.3 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	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	159	722000000 Hz	-2.6 dBmV	38.0 dB	1126 ~ 2969	388467542	1	0
2	Not Locked	0	0	0 Hz	0 dBmV	0.0 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

ChallD
Aspirant
Apr 24, 2019
I have the exact same problem.

brianiup
Guide
Apr 26, 2019
I don't believe that is correct with this firmware... I have the same issue on 1.01 US locked 3 channels with no issues.. when it went up to 2.02 I had TONS of T-3 and T-4 errors and US would not lock more then 1 channel...

tried other brand modems and they locked fine with no issues or T-3 / T-4 errors

My signal on US and DS are fine comcast verified this, no noise on the line either...

Comcast reverted my CM1150V firmware back to 1.01 and it immediatly locked all upstream channels with no flashing lights (US and DS are solid green now)... This has to be a firmware issue as it only happens in version 2.02
- Scott_UU
  Star
  Apr 26, 2019
  brianiup wrote:
  
  I don't believe that is correct with this firmware... I have the same issue on 1.01 US locked 3 channels with no issues.. when it went up to 2.02 I had TONS of T-3 and T-4 errors and US would not lock more then 1 channel...
  
  ...
  
  Comcast reverted my CM1150V firmware back to 1.01 and it immediatly locked all upstream channels with no flashing lights (US and DS are solid green now)... This has to be a firmware issue as it only happens in version 2.02
  
  Odd, that's different (much worse) than what I'm seeing.
  
  I have v2.02.03, am currently locking all provisioned channels US (4) and DS (31+OFDM), and have no errors in log. The LED keeps flashing as if some channel weren't locked, but in the Netgear GUI everything shows locked (I suppose the GUI could be wrong and the light could be right, no way to tell for sure).
  
  I got v2.02.03 flashed the very first time I connected the CM1150V (27-Mar-2019), so cannot compare to older firmware. Initially I had problems locking US channels and tons of t3/t4 errors, but that was a problem at the tap. When Comcast fixed that, the CM1150V (still with v2.02.03) immediately locked all provisioned channels and the t3/t4 errors stopped.
  
  I suspect the flashing LED I'm seeing is a firmware error, and am inclined to believe the GUI (and Comcast) which both say everything is fine regarding signal lock. Not sure about your problem -- sure does sound like it is related to the firmware upgrade though since it disappeared when you rolled back.