Community Forum

33MBPS Speed instead of 150, Low Power in low Frequency channels

Regular Visitor

33MBPS Speed instead of 150, Low Power in low Frequency channels

I have a netgear CM1100 modem that is a couple months old.  When we first got it, we were getting 160 MBPs+.  We were having internet issues yesterday and I checked and we  are only getting 33MBPs(measured with computer plugged directly into modem).   A tech came out today, didn't really seem familiar with looking at the channels powers from the modem.  I pointed out that the power levels are too low on one of the channels and last night I had seen a high number of uncorrected codewords on that channel.   He hooked up his device to our cable and said he was seeing an issue, and then he measured at the street and our house and thinks it is the drop.  I am not 100% sure he is right since he was saying upstream power was too low, which didn't make sense to me since the issue seems to be with the downstream.  Anyway, my question is, would an issue with the drop cause the power to be too low at the low frequencies?   Is an issue on just 1 or 2 channels enough to drop our speeds from 150-180MBPs to 33?  See screenshots of the downstream power levels.  Notice how they are lower at low frequencies and then stabelize to around 5dBmv at the higher frequencies.   The logs are showing some warnings.   

 

 

 

 

Diamond Problem Solver

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

You need both good upstream and downstream to be good not just one or the other for the modem to work properly. You have 2 channels for sure that in double digit negative and low SNR. It’s hard to call it the drop without seeing the tap’s number to compare and knowing where at your house levels were checked(ground block, modem etc).But if the tech said it was the drop, did they not replace it? Post the upstream if you can

I am a Retired Official Comcast Employee
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Regular Visitor

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Here is the upstream.  He checked at the house, ground block and the tap.  He said things were bad at the ground block and good at the tap, so that is why he thinks it is the drop.   He said he had to call maintenance to replace the drop.  It's about a 100 feet or so from the tap to the ground block.  He was a contractor, so I'm guessing he wasn't equiped to replace it.

 

netgear_ulupload stats

Expert

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

FWIW, 

The general public can't see your pics. Since you are a new poster, they likely need to be approved by a Forum Admin. Or you may need to make a minimum number of posts.

You could try hosting them at one of those free third-party pic hosting sites and post the link to them here.



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!
Regular Visitor

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Here is the link to the uplink power info

Regular Visitor

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Comcast Andrew - Are you able to check as to when maintenance will be contacting me to replace the drop?   

 

Here are my latest stats.  Large number of uncorrected codewords on channel 6, power increases as the channel frequency goes up.   

 

<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 33 657000000 Hz 5.6 dBmV 38.0 dB 3281232063 84 0
2 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0
3 Locked QAM256 6 489000000 Hz -21.5 dBmV 26.2 dB 250907463 3762276647 3555645350
4 Locked QAM256 7 495000000 Hz -14.3 dBmV 32.3 dB 3280047764 1489 0
5 Locked QAM256 8 507000000 Hz -3.0 dBmV 38.7 dB 3280053124 14 0
6 Locked QAM256 9 513000000 Hz 0.0 dBmV 39.2 dB 3280057011 8 0
7 Locked QAM256 10 519000000 Hz 1.7 dBmV 39.4 dB 3280061323 13 0
8 Locked QAM256 11 525000000 Hz 2.6 dBmV 39.4 dB 3280064291 12 0
9 Locked QAM256 12 531000000 Hz 3.1 dBmV 39.5 dB 3280080751 12 0
10 Locked QAM256 13 537000000 Hz 3.6 dBmV 39.2 dB 3280085354 12 0
11 Locked QAM256 14 543000000 Hz 3.9 dBmV 39.2 dB 3280090327 15 0
12 Locked QAM256 15 549000000 Hz 4.1 dBmV 39.3 dB 3280092788 19 0
13 Locked QAM256 16 555000000 Hz 4.5 dBmV 39.3 dB 3280095621 9 0
14 Locked QAM256 17 561000000 Hz 4.8 dBmV 39.1 dB 3280107068 12 0
15 Locked QAM256 18 567000000 Hz 5.0 dBmV 39.0 dB 3280130444 16 0
16 Locked QAM256 19 573000000 Hz 5.2 dBmV 39.1 dB 3280111892 18 0
17 Locked QAM256 20 579000000 Hz 5.3 dBmV 39.0 dB 3280179211 17 0
18 Locked QAM256 21 585000000 Hz 5.4 dBmV 39.0 dB 3280184748 22 0
19 Locked QAM256 22 591000000 Hz 5.6 dBmV 39.0 dB 3280164300 21 0
20 Locked QAM256 23 597000000 Hz 5.7 dBmV 38.8 dB 3280198266 19 0
21 Locked QAM256 24 603000000 Hz 5.7 dBmV 38.7 dB 3280201173 20 0
22 Locked QAM256 25 609000000 Hz 5.6 dBmV 38.6 dB 3280205283 34 0
23 Locked QAM256 26 615000000 Hz 5.5 dBmV 38.3 dB 3280208744 34 0
24 Locked QAM256 27 621000000 Hz 5.5 dBmV 38.3 dB 3280212995 50 0
25 Locked QAM256 28 627000000 Hz 5.6 dBmV 38.3 dB 3280215813 55 0
26 Locked QAM256 29 633000000 Hz 5.5 dBmV 38.2 dB 3280220424 49 0
27 Locked QAM256 30 639000000 Hz 5.6 dBmV 38.2 dB 3280223413 56 0
28 Locked QAM256 31 645000000 Hz 5.4 dBmV 38.1 dB 3280227249 64 0
29 Locked QAM256 32 651000000 Hz 5.5 dBmV 38.1 dB 3280230743 82 0
30 Locked QAM256 34 663000000 Hz 5.7 dBmV 38.1 dB 3280233614 73 0
31 Locked QAM256 35 669000000 Hz 5.7 dBmV 37.9 dB 3280235605 80 0
32 Locked QAM256 36 675000000 Hz 5.7 dBmV 38.0 dB 3280235610 86 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 5 35700000 Hz 43.3 dBmV
2 Locked ATDMA 6 29200000 Hz 42.3 dBmV
3 Locked ATDMA 7 22700000 Hz 41.3 dBmV
4 Locked ATDMA 8 16200000 Hz 40.8 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
Official Employee

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Hi @not_too_shabby

 

Thanks for posting to the Xfinity Forums. Sorry for the issues you're having. I'd like to see if I can get an update from your local maintenance team. Can you please send me a private message so I can pull up your account? To send a private message click on my name "ComcastChe", then click send a message. 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!
Regular Visitor

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Message sent

Official Employee

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Thank you! I've replied. I got a chance to reach out to your local line techs about your drop. You should be contacted soon about scheduling. I'll follow up with you in our private message in a few days. 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!
Regular Visitor

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Our drop was just replaced.  We are back up to 180MB/s and signal levels are normal.

 


<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 21 585000000 Hz 5.3 dBmV 38.7 dB 69462686 0 0
2 Locked QAM256 5 483000000 Hz 4.6 dBmV 39.5 dB 83495917 0 0
3 Locked QAM256 6 489000000 Hz 4.6 dBmV 39.4 dB 83501324 0 0
4 Locked QAM256 7 495000000 Hz 4.7 dBmV 39.4 dB 83505306 0 0
5 Locked QAM256 8 507000000 Hz 4.7 dBmV 39.2 dB 83508406 0 0
6 Locked QAM256 9 513000000 Hz 4.7 dBmV 39.2 dB 83512793 0 0
7 Locked QAM256 10 519000000 Hz 4.8 dBmV 39.1 dB 83516171 0 0
8 Locked QAM256 11 525000000 Hz 4.8 dBmV 39.2 dB 83519928 0 0
9 Locked QAM256 12 531000000 Hz 4.8 dBmV 39.2 dB 83523577 0 0
10 Locked QAM256 13 537000000 Hz 5.0 dBmV 39.0 dB 83527871 0 0
11 Locked QAM256 14 543000000 Hz 5.0 dBmV 39.0 dB 83531539 1 0
12 Locked QAM256 15 549000000 Hz 5.0 dBmV 38.9 dB 83534824 0 0
13 Locked QAM256 16 555000000 Hz 5.1 dBmV 39.0 dB 83538787 0 0
14 Locked QAM256 17 561000000 Hz 5.2 dBmV 38.6 dB 83543195 2 0
15 Locked QAM256 18 567000000 Hz 5.1 dBmV 38.8 dB 83546491 1 0
16 Locked QAM256 19 573000000 Hz 5.3 dBmV 38.7 dB 83550565 0 0
17 Locked QAM256 20 579000000 Hz 5.3 dBmV 38.7 dB 83553921 1 0
18 Locked QAM256 33 657000000 Hz 5.0 dBmV 38.0 dB 68000072 2 0
19 Locked QAM256 22 591000000 Hz 5.4 dBmV 38.7 dB 83561604 1 0
20 Locked QAM256 23 597000000 Hz 5.5 dBmV 38.5 dB 83564788 1 0
21 Locked QAM256 24 603000000 Hz 5.4 dBmV 38.3 dB 83568750 1 0
22 Locked QAM256 25 609000000 Hz 5.3 dBmV 38.3 dB 83572661 0 0
23 Locked QAM256 26 615000000 Hz 5.1 dBmV 38.0 dB 83576388 4 0
24 Locked QAM256 27 621000000 Hz 5.1 dBmV 38.1 dB 83580108 2 0
25 Locked QAM256 28 627000000 Hz 5.2 dBmV 38.1 dB 83584820 1 0
26 Locked QAM256 29 633000000 Hz 5.1 dBmV 37.9 dB 83588650 0 0
27 Locked QAM256 30 639000000 Hz 5.0 dBmV 38.1 dB 83591790 1 0
28 Locked QAM256 31 645000000 Hz 4.8 dBmV 37.7 dB 83596206 1 0
29 Locked QAM256 32 651000000 Hz 5.0 dBmV 37.9 dB 83599189 2 0
30 Locked QAM256 34 663000000 Hz 5.2 dBmV 37.8 dB 83602945 2 0
31 Locked QAM256 35 669000000 Hz 5.1 dBmV 37.8 dB 83605951 2 0
32 Locked QAM256 36 675000000 Hz 5.1 dBmV 37.8 dB 83606571 2 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 5 35700000 Hz 42.3 dBmV
2 Locked ATDMA 6 29200000 Hz 41.8 dBmV
3 Locked ATDMA 7 22700000 Hz 40.8 dBmV
4 Locked ATDMA 8 16200000 Hz 40.3 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
Official Employee

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Thanks for the follow-up @not_too_shabby. I've replied to your private message. If you have any more issues in the future, please let us know. Thanks for being the BEST part of Comcast, take care! 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!
Official Employee

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Thanks for allowing me to assist you @not_too_shabby! I appreciate you sticking through this with me. If you need any help in the future, feel free to contact us. Thank you for being a valued Comcast customer, take care! 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!
Expert

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Could the final solution please be shared here publicly so that all readers here may benefit ?


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!
Official Employee

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Sure @EG. In @not_too_shabby's situation, the issue was due to the drop. Since being replaced, there haven't been any more service issues. 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!
Expert

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

Thank you very much for replying ! 🙂


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!
Official Employee

Re: 33MBPS Speed instead of 150, Low Power in low Frequency channels

You're welcome! Smiley Happy 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!