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popfresk's avatar
popfresk
New Contributor
4 years ago

Intermittent Critical Modem Events

Recently I have been encountering upstream issues which appear to be tied to critical priority (tier 3) events in my modem's event log. I can still hear people talking to me over VoIP, but I cannot talk, and I cannot open new connections, such as opening a browser and accessing a web page.

My equipment: Netgear CM1200

The main errors I encounter:

  • SYNC Timing Synchronization failure - Loss of Sync
  • Received Response to Broadcast Maintenance Request, but no Unicast Maintenance opportunities received - T4 time out
  • No Ranging Response received - T3 time-out

I'm also getting some non-critical errors I think may be of significance:

  • REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value
  • RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW
  • Dynamic Range Window violation

These issues don't just occur during the day with increased use due to covid (alongside the increased ping and packet loss) - they will also happen randomly at say 4AM, when almost nobody is using the internet. These events are a complete loss of internet access, where during the day I can still access the internet. Many times the upstream light on my modem will start to blink (not always).

Sometimes, when I look at my ping to google which I constantly log for diagnostics, I'll see that the packet loss is on and off about every other second. During these situations, my internet is functioning barely. Some web pages will load slowly as it gets trickled in through the constant packet loss and loss of internet. 

No one else is using the internet in my house during these times, so I can safely say it's not an in-home use scenario.

How do I get someone to come out who has some actual technical knowledge that can troubleshoot this for me? I had a technician out today and it seems like he doesn't really know too much other than how to plug their device into the tap/coax in my house and tell me 'it looks good right now'. Not 30 minutes later and it's happening again to me. 

I have a feeling it's something to do with their lines up to my house, or perhaps the local node. But I don't want to jump to conclusions. 

connection issues
packet loss
sync timing synchronization failure
T3 time-out
T4 Time Out

4 Replies

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  • JonathanJ's avatar
    JonathanJ
    Former Moderator
    4 years ago
    @popfresk

    I apologize for the frustration you’ve been experiencing with your Cox services and I want to help. If you can email your full name and the street address on your Cox account to cox.help@cox.com, I’ll be happy to investigate.

    Jonathan J
    Cox Moderator
  • shallbetter's avatar
    shallbetter
    New Contributor
    4 years ago

    Wish I could help, but I'm having the same problem.  I did finally call in one day and get a very knowledgeable technician who found a mis-configuration on the cox side.  things improved for a month, but now I'm right back to the T4 and T3 Ranging issues. 

    I had hopes of a technician to come out and check, but it sounds like that isn't very useful either.  If I had another option, I'd be taking it.

    • JonathanJ's avatar
      JonathanJ
      Former Moderator
      4 years ago

      @shallbetter

      You can also email your account information so we can investigate.


      Jonathan J
      Cox Moderator
  • popfresk's avatar
    popfresk
    New Contributor
    4 years ago

    Here is an example of the issues I encounter. You can see that the connection is extremely intermittent on a few second scale. And that the issue persists for more than a few minutes.