U

Saturday, October 12th, 2024 1:53 AM

High Upstream Power Levels

My service seems to run fine however I am concerned with my upstream power levels. They look high from what I've normally seen online (>50dBmv). Uncorrectables seems like they are higher than I would expect but downstream snr and power seem fine.

Downstream Bonded Channels
Channel LockedStatus Modulation ChannelID  Frequency     Power    SNR   Correctables Uncorrectables     
      1     Locked     QAM256     25     669000000 Hz     -1.1     39.5     1414     23
      2     Locked     QAM256      2     531000000 Hz     -1.1     39.7     23620     1087
      3     Locked     QAM256      3     537000000 Hz     -1.4     39.7     30541     1218
      4     Locked     QAM256      4     543000000 Hz     -1.9     39.6     33249     1167
      5     Locked     QAM256      5     549000000 Hz     -1.5     39.6     40743     1393
      6     Locked     QAM256      6     555000000 Hz     -1.8     39.4     45093     1612
      7     Locked     QAM256      7     561000000 Hz     -1.9     39.4     45327     1583
      8     Locked     QAM256      8     567000000 Hz     -1.7     39.5     48880     1667
      9     Locked     QAM256      9     573000000 Hz     -1.6     39.4     50016     1867
     10     Locked     QAM256     10     579000000 Hz     -1.6     39.6     43279     1485
     11     Locked     QAM256     11     585000000 Hz     -1.6     39.5     48321     1702
     12     Locked     QAM256     12     591000000 Hz     -1.3     39.5     41353     1578
     13     Locked     QAM256     13     597000000 Hz     -1.3     39.5     47883     1814
     14     Locked     QAM256     14     603000000 Hz     -1.5     39.4     50759     1743
     15     Locked     QAM256     15     609000000 Hz     -1.3     39.4     44410     1453
     16     Locked     QAM256     16     615000000 Hz     -1.1     39.5     51749     2112
     17     Locked     QAM256     17     621000000 Hz     -1.2     39.5     56867     2555
     18     Locked     QAM256     18     627000000 Hz     -1.3     39.3     62490     2909
     19     Locked     QAM256     19     633000000 Hz     -0.8     39.5     71807     3923
     20     Locked     QAM256     20     639000000 Hz     -1     39.4     80632     5943
     21     Locked     QAM256     21     645000000 Hz     -0.9     39.3     4075     1030
     22     Locked     QAM256     22     651000000 Hz     -0.9     39.4     7377     1033
     23     Locked     QAM256     23     657000000 Hz     -0.8     39.5     11368     1072
     24     Locked     QAM256     24     663000000 Hz     -1.1     39.5     13737     1045
     25     Locked     QAM256     26     675000000 Hz     -1.1     39.2     2300     1055
     26     Locked     QAM256     27     681000000 Hz     -1.6     39.5     2573     1109
     27     Locked     QAM256     28     687000000 Hz     -1.5     39.7     2943     1036
     28     Locked     QAM256     29     693000000 Hz     -1     39.9     3093     1029
     29     Locked     QAM256     30     699000000 Hz     -0.7     40     2701     1040
     30     Locked     QAM256     31     705000000 Hz     -0.4     40     2276     1079
     31     Locked     QAM256     32     711000000 Hz     0     40     2575     1035
     32     Not Locked     Unknown      0     0 Hz     0.0     0.0     0     0

Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power     
      1       Locked       ATDMA      9       2560 Ksym/sec       40400000 Hz       50.5 dBmV
      2       Locked       ATDMA      1       5120 Ksym/sec       35600000 Hz       51.5 dBmV
      3       Locked       ATDMA      2       5120 Ksym/sec       29200000 Hz       52.3 dBmV
      4       Locked       ATDMA      3       5120 Ksym/sec       22800000 Hz       52.8 dBmV
      5       Locked       ATDMA      4       5120 Ksym/sec       16400000 Hz       54.3 dBmV
      6       Not Locked       Unknown      0       0       0       0.0
      7       Not Locked       Unknown      0       0       0       0.0
      8       Not Locked       Unknown      0       0       0       0.0

Downstream OFDM Channels
Channel   LockedStatus  ProfileID  ChannelID    Frequency       Power       SNR/MER    ActiveSubcarrier    Unerror    Correctable   Uncorrectable
      1     Locked     0 ,1 ,2 ,3     37     762000000 Hz     -0.62 dBmV     40.2 dB     1108 ~ 2987     11662612097     11481176955     38956
      2     Not Locked     0      0     0 Hz     0 dBmV     0 dB     0 ~ 4095     0     0     0

Upstream OFDMA Channels
Channel   LockedStatus    ProfileID    ChannelID    Frequency       Power
      1     Not Locked     0      0     0 Hz     0 dBmV
      2     Not Locked     0      0     0 Hz     0 dBmV

Expert

 • 

107K Messages

1 month ago

You are correct. It's a connectivity problem just waiting to happen ! Channels 3-5 are already out of spec, with 5 being the worst. Here are some things that you can try;

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.


Good luck with it !

Official Employee

 • 

1.6K Messages

30 days ago

 

user_mg0l2q Thank you so much for your post for help with your signal levels. @EG is on point as always have you had a chance to take a look at EGs comment? Let me know if you still need additional assistance we are always happy to help get a technician out for you if needed.

 

2 Messages

@XfinityAmandaB@EG 

Thank you! Indeed I removed one splitter inside and the upstream transmit levels have dropped to below 50 for all but 1. One channel is just over at 50.x. Removing the second splitter is not really possible as it is located outside and is providing MOCA connectivity to part of the house. I'm guessing if I could remove the other splitter the signals would get even better.

Official Employee

 • 

1.2K Messages

Thank you for the update @user_mg0l2q. Let us know here if removing the other splitter makes a difference as well. 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Expert

 • 

107K Messages

@XfinityJohnG​ 

They need it for MoCA.....

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? Please mark an Accepted Answer!tick

Expert

 • 

107K Messages

29 days ago

@user_mg0l2q 

Your guess would be correct. That is not much wiggle room but it may be OK if it remains stable. There is still some excess line attenuation somewhere. Bottom line. Live with it for a while and see if a connectivity / dropout problem happens. Good luck ! Please post back with an update.

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