C

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8 Messages

Friday, March 24th, 2023 6:09 PM

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T3/T4 timeouts and tons of uncorrectable errors

I have been having issues with Xfinity service for a while now and it is progressively getting worse.  I  had a tech out in September/October timeframe last year and he removed an amp telling me that was the issue, but have seen zero improvement.  In fact it is worse and from what I notice especially when it is raining or snowing.  I know the modem is not the issue or my router which is also new and experienced the same problems on my last 2 sets of routers/modems, but recently it is much worse.
  I am getting tons of uncorrectable errors along with tons of T3/T4 timeouts, which the T4 timeouts are disruptive as the modem connection is resetting.  Also when getting many T3 timeouts I see degradation of speed and packet loss.  Just to reiterate I have a brand new modem and router as well as testing the cable I have from the drop to my modem.  That test shows no shorts etc.  There are no splitters/amps.  Overall not really happy and now that I am working from home this is becoming especially frustrating when the internet disconnects 10+ times a day.

I also many times can see my Upstream status go to poor from the modem.  I have also seen 4 out of the 5 upstream bonded channels go to Unknown, as well as having Downstream bonded channels become Not Locked.

 Upstream Status: Poor
    Partial Service: Poor
    Cable modem is in partial service mode. Your service provider might be under maintenance. Most of the time it won't affect your traffic and will automatically clear when work is complete.
    Upstream Power Level: Good

Here are the event logs (after I reset modem) and power/SNR before the reset.
Time Priority Description
Fri Mar 24 09:47:44 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Fri Mar 24 09:35:27 2023 (Critical (3)) No Ranging Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Fri Mar 24 09:35:21 2023 (Notice (6)) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Fri Mar 24 09:35:15 2023 (Notice (6)) TLV-11 - unrecognized OID;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Time Not Established (Notice (6)) Honoring MDD; IP provisioning mode = IPv6
Time Not Established (Critical (3)) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Fri Mar 24 09:10:39 2023     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 23:58:33 2023     Critical (3)     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 23:56:09 2023     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:35:34 2023     Notice (6)     CM-STATUS message sent. Event Type Code: 4; Chan ID: 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:35:19 2023     Warning (5)     MDD message timeout;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:34:25 2023     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:07:27 2023     Notice (6)     CM-STATUS message sent. Event Type Code: 4; Chan ID: 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:07:05 2023     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:06:57 2023     Warning (5)     MDD message timeout;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 22:04:35 2023     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:50:47 2023     Notice (6)     CM-STATUS message sent. Event Type Code: 4; Chan ID: 14 15 16 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:50:27 2023     Warning (5)     MDD message timeout;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:49:19 2023     Critical (3)     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:46:17 2023     Warning (5)    TCS Partial Service;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:35:02 2023 (Critical (3)) No Ranging Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:35:01 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:35:01 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 21:28:40 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 20:45:31 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 20:40:20 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 19:58:01 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 19:08:12 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 18:45:42 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 18:09:07 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 18:05:47 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 16:31:25 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 15:50:28 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 14:30:09 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 10:22:05 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 10:21:44 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 09:55:21 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 09:49:17 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 09:45:44 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 09:40:11 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Thu Mar 23 09:38:40 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 18:39:09 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 18:37:54 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 17:45:41 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 17:33:18 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 17:30:03 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 17:23:35 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 17:03:18 2023 (Critical (3)) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 17:02:41 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 16:47:12 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 16:41:49 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 16:14:05 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 16:12:23 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;
Wed Mar 22 15:29:21 2023 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[[mac_cleared]];CMTS-MAC=[[mac_cleared]];CM-QOS=1.1;CM-VER=3.1;



Downstream Bonded Channels
Channel LockedStatus Modulation ChannelID  Frequency     Power    SNR   Correctables Uncorrectables    
      1     Locked     QAM256     12     495000000 Hz     2.6     41.6     20503440    37632958
      2     Locked     QAM256      1     423000000 Hz     4.1     41.9     12587053     17015643
      3     Locked     QAM256      2     435000000 Hz     4.1     42       14005345     20058872
      4     Locked     QAM256      3     441000000 Hz     4       42       14673142     21668820
      5     Locked     QAM256      4     447000000 Hz     3.9     42       15382722     23362188
      6     Locked     QAM256      5     453000000 Hz     3.8     41.9     16056171     25169715
      7     Locked     QAM256      6     459000000 Hz     3.5     41.9     16845156     27103804
      8     Locked     QAM256      7     465000000 Hz     3.4     41.9     17619969     29346118
      9     Locked     QAM256      8     471000000 Hz     3.4     41.9     18609525     32165257
     10     Locked     QAM256      9     477000000 Hz     3.3     41.9     19288189     34086690
     11     Locked     QAM256     10     483000000 Hz     3.1     41.8     19531431     34814774
     12     Locked     QAM256     11     489000000 Hz     2.8     41.7     19968170     35999369
     13     Locked     QAM256     13     501000000 Hz     2.4     41.6     21144450     39492283
     14     Locked     QAM256     14     507000000 Hz     2.1     41.4     21821147     41361301
     15     Locked     QAM256     15     513000000 Hz     2.1     41.5     22316637     43150952
     16     Locked     QAM256     16     519000000 Hz     2.1     41.4     22897409     44963466
     17     Locked     QAM256     17     525000000 Hz     2.3     41.4     23345743     46545478
     18     Locked     QAM256     18     531000000 Hz     2.3     41.4     23941345     48469724
     19     Locked     QAM256     19     537000000 Hz     2.3     41.3     24457716     50182931
     20     Locked     QAM256     20     543000000 Hz     2.2     41.2     24972778     51903086
     21     Locked     QAM256     21     555000000 Hz     1.3     40.9     26170763     55683482
     22     Locked     QAM256     22     561000000 Hz     0.7     40.5     26926469    57827026
     23     Locked     QAM256     23     567000000 Hz     0.6     40.4     27515432     59560264
     24     Locked     QAM256     24     573000000 Hz     0.5     40.4     27806678    60899986
     25     Locked     QAM256     25     579000000 Hz     0.7     40.5     28024663    62115403
     26     Locked     QAM256     26     585000000 Hz     1.1     40.7     28235843     63362442
     27     Locked     QAM256     27     591000000 Hz     1.3     40.8     28454265     64530970
     28     Locked     QAM256     28     597000000 Hz     1.2     40.8     28812206     66015544
     29     Locked     QAM256     29     603000000 Hz     1.2     40.8     29120969     67344660
     30     Locked     QAM256     30     609000000 Hz     0.8     40.8     29413839    68511477
     31     Locked     QAM256     31     615000000 Hz     1.1     40.9     29549079     69450019
     32     Locked     QAM256     32     621000000 Hz     1.1     40.9     29801260     70502885

Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power    
      1       Locked       ATDMA      5       2560 Ksym/sec       40400000 Hz       40.3 dBmV
      2       Locked       ATDMA      1       5120 Ksym/sec       35600000 Hz       39.3 dBmV
      3       Locked       ATDMA      2       5120 Ksym/sec       29200000 Hz       40.0 dBmV
      4       Locked       ATDMA      3       5120 Ksym/sec       22800000 Hz       40.5 dBmV
      5       Locked       ATDMA      4       5120 Ksym/sec       16400000 Hz       40.0 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     193     702000000 Hz     2.88 dBmV     39.4 dB     1108 ~ 2987     6043745406     3543152326     9617
      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

Gold Problem Solver

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26.3K Messages

2 years ago

... I also many times can see my Upstream status go to poor from the modem.  I have also seen 4 out of the 5 upstream bonded channels go to Unknown, as well as having Downstream bonded channels become Not Locked. ​ ...

Intermittent network connection problems are often due to poor coax connections or damaged coax cable, usually in or near your home. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power. RF noise, or problems further upstream are also possible.

If you want to troubleshoot this yourself, please see Internet Troubleshooting Tips. If you can't find the problem or you'd rather have Comcast take care of it and an employee does not respond to your message here, call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. It's not likely they can fix the problem remotely. If not, insist they send a tech out to identify the cause and correct it.

If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit ($70-$100) unless you have their Service Protection Plan ( https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device or anything outside your home you shouldn't be charged.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

Visitor

 • 

8 Messages

2 years ago

As I said there are no splitters or amps.  The cable was checked along with connections.

Gold Problem Solver

 • 

26.3K Messages

2 years ago

... The cable was checked along with connections.

If it was tested with a continuity checker, it could still have problems carrying RF. Even if checked with more sophisticated equipment it could still be intermittent, as the symptoms appear to be intermittent. And interference and problems upstream are still possible. Suggest you have Comcast check it out again.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

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