Community Forum

Getting a higher level of support for T3 timeouts and random disconnects

Highlighted
New Poster

Getting a higher level of support for T3 timeouts and random disconnects

Hi Folks, 

I've been dealing with Comcast support on this issue since Aug 25th, and I'm going in circles and am looking for some help.

 

My internet and phone will randomly stop working.  Phone has dialtone, but either can't dial out, or if it can the voice is so garbled people can't understand you.  Internet just appears dead.  The modem looks normal from a lights perspecitve.  

 

If I call tech support and the automated system does a reset, or I power cycle the modem, 9 out of 10 times it will come back.  The 10th time it won't and it will take an hour or 2 to reconnect.

 

When the modem goes into this state, I'd say about 50% of the time I can login to the interface at 10.0.0.1 the other 50% of the time I can't.  I don't know if the FW is locked up, its stuck in a loop or what.  When I can get in, I see many T3 timeout errors such as this:

 

[Docsis][950]: Unicast Maintenance Ranging attempted - No response - Retries exhausted
2020/9/15 17:57:22 Critical

[Docsis][950]: Ranging Request Retries exhausted
2020/9/15 17:57:22 Critical

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:57 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:56 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:55 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:53 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:52 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:51 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:50 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:49 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:47 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:46 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:45 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:44 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:42 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:41 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:40 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:56:39 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:49 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:48 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:47 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:46 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:44 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:43 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:42 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:41 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:39 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:38 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:37 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:36 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:34 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:33 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:32 Warning

[Docsis][950]: No Ranging Response received - T3 time-out
2020/9/15 17:53:31 Warning

I can get over 200 of those entries a day sometimes within an hour or 2 period.

 

Comcast has "thrown darts at the wall" trying to fix this by

  1. Replacing my modem on 8/27
  2. Replacing the amp feeding my street/cul-de-sac on 8/28
  3. Cutting off and replacing all the F connectors at
    1. The Tap
    2. The Comcast Side of the Grounding Block on my house
    3. The cable leading from the Grounding Block directly to my modem.
  4. Trying to upgrade me to the next higher performance tier (I said no, but somehow an order got put in anyways, which then messed up a service call)
  5. Another tech came out on 9/15 but when I told him my story above he just said its a neighborhood problem and didn't do anything.  Also tried to blame it on the fires (which I'm not near), and general covid congestion.  Up until Aug 25th I had no problems. All spring and summer sheltering at home things worked fine, so I don't buy either of those two answers.  I get COVID congestion might cause slowdowns, but that's not what I'm seeing.

Yes, I run my modem in bridge mode and use my own router, but since this is also taking out the phone I can't fathom how anytihng on my router could be involved.

 

I have a solid piece of Coax from my grounding block to my modem.   No splitters, no TVs, no extra cable looped up. 

 

I even crawled under the house and in my attic where the COAX runs to inspect it just to make sure some rodent hadn't gotten into my house and chewed on it.  Looks perfect (ok, I can't inspect the portion in the wall where it goes up from my crawlspace into my attic) and has no damage.

 

Here's the data from my XFINITY network stats page on the modem:

Downstream Data:

                           Channel Bonding Value
Index                      1          2          3          4          5          6        
Lock Status                Locked     Locked     Locked     Locked     Locked     Locked    
Frequency                  549 MHz    447 MHz    453 MHz    459 MHz    465 MHz    471 MHz  
SNR                        38.605 dB  38.605 dB  38.605 dB  38.983 dB  38.983 dB  38.605 dB
Power Level                2.400 dBmV 5.200 dBmV 5.300 dBmV 5.200 dBmV 4.900 dBmV 4.500 dBmV
Modulation                 256 QAM    256 QAM    256 QAM    256 QAM    256 QAM    256 QAM  

Index                      7          8          9          10         11         12        
Lock Status                Locked     Locked     Locked     Locked     Locked     Locked    
Frequency                  477 MHz    483 MHz    489 MHz    495 MHz    507 MHz    513 MHz  
SNR                        38.983 dB  38.983 dB  38.983 dB  38.605 dB  38.605 dB  38.983 dB
Power Level                4.500 dBmV 4.700 dBmV 4.800 dBmV 4.800 dBmV 4.500 dBmV 4.100 dBmV
Modulation                 256 QAM    256 QAM    256 QAM    256 QAM    256 QAM    256 QAM  

Index                      13         14         15         16         17         18        
Lock Status                Locked     Locked     Locked     Locked     Locked     Locked    
Frequency                  519 MHz    525 MHz    531 MHz    537 MHz    543 MHz    555 MHz  
SNR                        38.983 dB  38.983 dB  38.983 dB  38.605 dB  38.605 dB  38.983 dB
Power Level                3.700 dBmV 3.600 dBmV 3.400 dBmV 3.100 dBmV 2.700 dBmV 2.400 dBmV
Modulation                 256 QAM    256 QAM    256 QAM    256 QAM    256 QAM    256 QAM  

Index                      19         20         21         22         23         24
Lock Status                Locked     Locked     Locked     Locked     Locked     Locked
Frequency                  561 MHz    567 MHz    573 MHz    579 MHz    585 MHz    591 MHz
SNR                        38.605 dB  38.605 dB  38.983 dB  38.605 dB  38.605 dB  38.605 dB
Power Level                2.500 dBmV 2.700 dBmV 3.000 dBmV 3.300 dBmV 3.600 dBmV 3.800 dBmV
Modulation                 256 QAM    256 QAM    256 QAM    256 QAM    256 QAM    256 QAM

Upstream Data:

                          Channel Bonding Value
Index                      1             2             3             4             5
Lock Status                Locked        Locked        Locked        Locked        Locked
Frequency                  36 MHz        17 MHz        30 MHz        41 MHz        23 MHz
Symbol Rate                5120 KSym/sec 5120 KSym/sec 5120 KSym/sec 1280 KSym/sec 5120 KSym/sec
Power Level                41.500 dBmV   40.250 dBmV   41.750 dBmV   38.500 dBmV   41.250 dBmV
Modulation                 64 QAM        64 QAM        64 QAM        64 QAM        64 QAM
Channel Type               ATDMA         ATDMA         ATDMA         ATDMA         ATDMA

CM Error Codewords

Unerrored Codewords        2359407530 2358091230 2358112177 2358106369 2358108318 2358094021
Correctable Codewords      1129       3672       2581       2635       2648       2527      
Uncorrectable Codewords    7473       20047      17833      15767      12358      16663      

Unerrored Codewords        2358074205 2358082791 2358087875 2358091118 2358061403 2358071743
Correctable Codewords      1491       2011       2332       30209      2583       2605      
Uncorrectable Codewords    10927      13860      8070       10699      18182      17876    

Unerrored Codewords        2358107690 2358068267 2358093603 2358093346 2358071294 2358079889
Correctable Codewords      2333       2340       2495       1856       1691       328      
Uncorrectable Codewords    16117      18502      17635      13082      10506      1236      

Unerrored Codewords        2358106077 2358068714 2358062084 2358092162 2358080606 2358060740
Correctable Codewords      153        118        103    92       100       84
Uncorrectable Codewords    1          1          0        0       0       0

I've spent hours on the phone with techs.  Some are good, some are not.  One told me my SNR and by BER were too high on the upstream channel.  I was supposed to have a supervisor call me yesterday, but they didn't.

 

I am now looking to get some sort of a higher level tech out here who can hook up a meter, signal anaylzer, TDR or whatever you use on DOCSIS to start looking for the problem.  I would expect something like this:

  1. Hook meter at Grounding Block.  Signal Bad.  Move to Tap.
  2. Hook meter to Tap, Signal still bad, Move to Amp.
  3. Hook meter to Amp, Signal still bad, move to next point up the line,
  4. Etc, etc, etc until the problem is identified.

 I admit that I'm no DOCSIS expert, but if I was trying to solve an issue like this on the LAN/WAN at work this is an approach I would take.  Personally I suspect something at the head-end.  I think that's the CMTS but I don't know (nor do I know where that's located, but I assume somewhere in my neighborhood because I believe its near the HFC node).

 

Does anyone here know how to escalate this?  1-800-comcast isn't getting me there.  I mean the folks are nice, but they are running from the script.  The famliy has their pitchforks out blaming me everytime "Dad, the WiFi is down again".

 

Help, Insights, and pointers appreciated.

 

Thanks,

Brian.