Forum Discussion

tgies's avatar
tgies
New Contributor
6 years ago

Cox system won't "let" techs schedule service call to remove old filter, so no docsis 3.1

Hi,

I recently upgraded to a DOCSIS 3.1 modem and Gigablast and I have what is pretty clearly the textbook problem where an old analog filter on the line blocks channels below about 600MHz, preventing DOCSIS 3.1 from fully working and limiting my speeds to ~600mbps. I can log into the modem's built-in spectrum analyzer and see that I have great signal down to 600MHz, where it abruptly drops off. The modem status page indicates I am only connecting on 20 channels, and the remaining channels have a null signal level. The status light on my SB8200 which lights green for DOCSIS 3.0 or blue for DOCSIS 3.1 is lit green.

Despite all this, when I call Cox support, their "system check" says my modem is working "perfectly" and supposedly "will not let" them create the service call for the tech to come remove the filter. This should be trivial to address but I can't get it addressed.

Has anyone gotten a similar issue resolved? Is there a moderator here who could reach in and get this call scheduled for me?

DOCSIS 3.1
filter
Gigablast
sb8200
service request
  • tgies's avatar
    tgies
    New Contributor
    6 years ago

    Here's the modem specan showing what I think is clear evidence of the filter: https://i.imgur.com/2T9lRJ6.png

    And here's the channel status dump:

    Downstream Bonded Channels
    Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
    22 Locked QAM256 909000000 Hz 5.3 dBmV 40.8 dB 0 0
    1 Locked QAM256 783000000 Hz 9.3 dBmV 41.6 dB 0 0
    2 Locked QAM256 789000000 Hz 9.2 dBmV 41.6 dB 0 0
    3 Locked QAM256 795000000 Hz 9.6 dBmV 41.9 dB 0 0
    4 Locked QAM256 801000000 Hz 9.3 dBmV 41.7 dB 0 0
    9 Locked QAM256 831000000 Hz 8.9 dBmV 41.7 dB 0 0
    10 Locked QAM256 837000000 Hz 8.6 dBmV 41.6 dB 0 0
    11 Locked QAM256 843000000 Hz 8.4 dBmV 41.6 dB 0 0
    12 Locked QAM256 849000000 Hz 8.3 dBmV 41.7 dB 0 0
    17 Locked QAM256 879000000 Hz 6.6 dBmV 41.4 dB 0 0
    18 Locked QAM256 885000000 Hz 5.9 dBmV 41.0 dB 0 0
    19 Locked QAM256 891000000 Hz 5.5 dBmV 41.0 dB 0 0
    20 Locked QAM256 897000000 Hz 4.9 dBmV 40.7 dB 0 0
    21 Locked QAM256 903000000 Hz 4.8 dBmV 40.7 dB 0 0
    25 Locked QAM256 927000000 Hz 5.3 dBmV 40.6 dB 0 0
    26 Locked QAM256 933000000 Hz 5.5 dBmV 40.9 dB 0 0
    27 Locked QAM256 939000000 Hz 5.4 dBmV 40.7 dB 0 0
    28 Locked QAM256 945000000 Hz 5.5 dBmV 40.7 dB 0 0
    29 Locked QAM256 951000000 Hz 5.5 dBmV 40.6 dB 0 0
    30 Locked QAM256 957000000 Hz 5.2 dBmV 40.6 dB 0 0
    33 Not Locked Unknown 357000000 Hz -39.4 dBmV 0.0 dB 0 0
    34 Not Locked Unknown 363000000 Hz -39.2 dBmV 0.0 dB 0 0
    35 Not Locked Unknown 369000000 Hz -39.0 dBmV 0.0 dB 0 0
    36 Not Locked Unknown 375000000 Hz -39.0 dBmV 0.0 dB 0 0
    37 Not Locked Unknown 381000000 Hz -39.0 dBmV 0.0 dB 0 0
    38 Not Locked Unknown 387000000 Hz -38.9 dBmV 0.0 dB 0 0
    41 Not Locked Unknown 405000000 Hz -39.5 dBmV 0.0 dB 0 0
    42 Not Locked Unknown 411000000 Hz -39.3 dBmV 0.0 dB 0 0
    43 Not Locked Unknown 417000000 Hz -39.2 dBmV 0.0 dB 0 0
    44 Not Locked Unknown 423000000 Hz -38.7 dBmV 0.0 dB 0 0
    45 Not Locked Unknown 429000000 Hz -38.0 dBmV 0.0 dB 0 0
    46 Not Locked Unknown 435000000 Hz -37.2 dBmV 0.0 dB 0 0
    159 Locked Other 300000000 Hz -38.3 dBmV 0.0 dB 0 0

    Upstream Bonded Channels
    Channel Channel ID Lock Status US Channel Type Frequency Width Power
    1 4 Locked SC-QAM 36700000 Hz 6400000 Hz 35.1 dBmV
    2 1 Locked SC-QAM 17400000 Hz 6400000 Hz 30.9 dBmV
    3 2 Locked SC-QAM 23900000 Hz 6400000 Hz 31.9 dBmV
    4 3 Locked SC-QAM 30300000 Hz 6400000 Hz 33.4 dBmV
  • CrystalS's avatar
    CrystalS
    Former Moderator
    6 years ago
    @tgies Hello. I would like to really investigate this for you. Thank you for the information. Please email us at cox.help@cox.com. Please allow us to research and work on fulfilling the request for you. -Crystal
  • KevinM2's avatar
    KevinM2
    Former Moderator
    6 years ago
    Hi Tgies, thank you for reaching out to us via email regarding your speeds. As of now, an outage has been declared in your area. When this outage clears, can you please perform a speed test on a hard-wired connection, using the Cox Internet Speed Test tool?

    http://bit.ly/2VsdGbX

    We'd like to see what speeds you are obtaining on a hard-wired connection. -Kevin M. Cox Support Forum Moderator