azdeltawye's profile

Frequent Visitor

 • 

45 Messages

Mon, Apr 26, 2021 10:47 PM

IPv4 Packet loss on windy afternoons

Hello,

I have been working from home for over a year now and my Comcast/Xfinity internet performance has been very reliable, until now...

Starting on 4/21, my connection has been experiencing severe intermittent packet loss (1% - 20%). This seems to happen around 13:00 and continues until about 17:00, especially when its windy outside. I logged into my modem to check the logs (Motorola MB8600) and nothing over a notice level 6 (message sent). My signal-noise and signal levels are very good (SNR: 39.4 - 40.1 dB) and -2 to 0.2 dBmV respectively on the main channels (1-32). My OFDM channel 33, however, is not very healthy at all with a SNR of 0 dB and signal level of -7.1 dBmV. Speed tests have been fine, even in the afternoons, 80-100/4-6 Mbps on a 100/5 Mbps tier.

Any idea of how to troubleshoot further? I think the problem is upstream with the CMTS but getting comcast/xfinity to do anything other than take my monthly payment seems unlikely at best...

One more tidbit, which may be significant, there have been two new cable hookups in my neighborhood recently; one neighbor on my node and another on an adjacent circuit. This seems more causal than coincident. 

Oh, one last detail: I'm only having trouble on IPv4, my IPv6 connection seems to be pretty solid. Unfortunately my work VPN only supports IPv4 so that doesn't help much..

Any help would be greatly appreciated!

This post was escalated on April 27, 2021 by EG

Responses

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Update: After resetting modem, all the non-critical event logs were cleared and revealed more meaningful error logs - see below. Also, the OFDM channel (33) appears to be locked and healthy now.

   

Time Not Established

 

Notice (6)

 

Honoring MDD; IP provisioning mode = IPv6

   

20:07:18
Mon Apr 26 2021

 

Notice (6)

 

DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

   

20:07:24
Mon Apr 26 2021

 

Warning (5)

 

REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

(edited)

EG

Expert

 • 

87.2K Messages

@azdeltawye 

FWIW. There is a known glitch with some makes / models of modem's firmware where the measuring mechanism incorrectly reads the power level, the SNR, and the bit errors for the OFDM channel. So it reads many errors when there really aren't.

That said. Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers in their entirety. And the balance of the error log entries in their entirety.

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Thanks for the reply!

Here are current screenshots of my modem status..

Downstream Status

Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 33 657.0 0.6 39.5 13 0
   2 Locked QAM256 13 531.0 2.1 40.0 0 0
   3 Locked QAM256 14 537.0 2.3 40.0 0 0
   4 Locked QAM256 15 543.0 1.9 39.8 0 0
   5 Locked QAM256 16 555.0 1.8 39.6 0 0
   6 Locked QAM256 17 561.0 1.9 39.7 0 0
   7 Locked QAM256 18 567.0 1.8 39.6 0 0
   8 Locked QAM256 19 573.0 1.7 39.6 0 0
   9 Locked QAM256 20 579.0 1.7 39.7 0 0
   10 Locked QAM256 21 585.0 1.7 39.6 0 0
   11 Locked QAM256 22 591.0 1.7 39.6 0 0
   12 Locked QAM256 23 597.0 1.9 39.5 0 0
   13 Locked QAM256 24 603.0 1.7 39.5 1 0
   14 Locked QAM256 25 609.0 1.5 39.5 1 0
   15 Locked QAM256 26 615.0 1.4 39.5 0 0
   16 Locked QAM256 27 621.0 1.4 39.5 0 0
   17 Locked QAM256 28 627.0 1.2 39.5 0 0
   18 Locked QAM256 29 633.0 1.2 39.5 1 0
   19 Locked QAM256 30 639.0 1.0 39.5 1 0
   20 Locked QAM256 31 645.0 0.9 39.6 0 0
   21 Locked QAM256 32 651.0 0.8 39.4 1 0
   22 Locked QAM256 34 663.0 0.6 39.7 51 0
   23 Locked QAM256 35 669.0 0.4 39.6 80 14
   24 Locked QAM256 36 675.0 0.3 39.0 79 53
   25 Locked QAM256 37 681.0 0.1 39.7 112 56
   26 Locked QAM256 38 687.0 -0.2 39.5 65 180
   27 Locked QAM256 39 693.0 -0.8 39.5 70 340
   28 Locked QAM256 40 699.0 -1.5 39.2 113 521
   29 Locked QAM256 41 705.0 -2.7 38.7 151 740
   30 Locked QAM256 42 711.0 -4.3 37.9 162 804
   31 Locked QAM256 43 717.0 -4.3 37.8 122 691
   32 Locked QAM256 44 723.0 -3.2 38.4 95 453
   33 Locked OFDM PLC 159 805.0 0.1 39.3 4918282 0

Upstream Status

 Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 5120 16.4 40.8
   2 Locked SC-QAM 2 5120 22.8 40.8
   3 Locked SC-QAM 3 5120 29.2 41.3
   4 Locked SC-QAM 4 5120 35.6 41.3
   5 Locked SC-QAM 5 2560 40.4 41.8

Event Log

 Event Log  
  
    Time    Priority    Description 
    01:13:59
Fri Jan 8 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:06
Fri Jan 8 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:07
Fri Jan 8 2021
  Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:17
Fri Jan 8 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:22
Fri Jan 8 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:27
Fri Jan 8 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:27
Fri Jan 8 2021
  Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:14:37
Fri Jan 8 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:16:01
Fri Jan 8 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    01:16:04
Fri Jan 8 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    20:13:23
Fri Jan 15 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:08:41
Tue Jan 19 2021
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
    16:22:19
Mon Mar 29 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:48:46
Sun Apr 4 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:19:08
Wed Apr 7 2021
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:20:06
Wed Apr 7 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:30:06
Wed Apr 7 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:30:08
Wed Apr 7 2021
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:30:28
Wed Apr 7 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:30:36
Wed Apr 7 2021
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:30:48
Wed Apr 7 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:30:52
Wed Apr 7 2021
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:31:34
Wed Apr 7 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:31:46
Wed Apr 7 2021
  Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:32:11
Wed Apr 7 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:32:31
Wed Apr 7 2021
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    09:34:02
Wed Apr 7 2021
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
    Time Not Established   Notice (6)   Honoring MDD; IP provisioning mode = IPv6
    20:07:18
Mon Apr 26 2021
  Notice (6)   DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    20:07:24
Mon Apr 26 2021
  Warning (5)   REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

(edited)

This comment was created from this reply
EG

Expert

 • 

87.2K Messages

@azdeltawye

The signal stats are o/k but the error log entries indicate that something is going on. Perhaps there is noise ingress into the line(s) /  an upstream channel-return path impairment somewhere.


There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.

I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS to see whether or not everything is in the green zone, see your node / cable plant and modem health, and also see a history plot for the modem. You should get a reply here in your topic. Good luck !

 

Official Employee

 • 

2.5K Messages

Hi there, . Thanks for posting here for support. So many of us are working from home nowadays, we certainly understand the urgency/need behind having a strong and stable internet connection. As you can see, we are here to help! I want to run through a few things here first. It's interesting that you only experience problems on the IPv4 connection, not the IPv6, so that is definitely good to note. When you experience a connection issue during the day and outside of the modem logs, have you been able to confirm other devices that are not connected to the VPN experience a similar delay/drop in the connection?

azdeltawye

Frequent Visitor

 • 

45 Messages

Thanks for the reply!

Yes, everything on my private network is affected by the packet loss anomalies.

(edited)

Official Employee

 • 

2.5K Messages

Got it. Thank you so much for sharing! May I see a screenshot of the Uncorrectable Errors that your modem is reporting as well? I noticed the Correctable errors, but I would like to take a look at the Uncorrectable ones as well.

Official Employee

 • 

2.5K Messages

We would like to go ahead and look at some additional diagnostics on our end. The T3 timeouts and Uncorrectable Errors are going to be our main focus and we'll toward helping you reach a solution. Please click on the chat icon in the upper right-hand corner of this page and initiate a chat with Xfinity Support. Be sure to include your first and last name, along with your full address. We'll respond from there. Thanks!

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Update; the Comcast/Xfinity technician stopped by yesterday and indicated everything looked great. He hooked up his test modem and said everything was within spec. He did remove a 3 dB attenuator on the line that a previous tech had installed several years ago. He said that he couldn't see a need for it and said it might even help..

Flash forward to today and the packet loss is back...

Here is the current modem status and signal levels. Notice the received power levels have increased about 3 dB which is expected. Also notice that there are a fairly large number of uncorrectable errors.

 System Up Time 2 days 20h:28m:31s  
  
   Network Access Allowed  
  


   Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 21 585.0 2.3 39.2 77 132
   2 Locked QAM256 1 459.0 4.0 40.3 0 0
   3 Locked QAM256 2 465.0 3.9 40.2 1597 3057
   4 Locked QAM256 3 471.0 3.7 40.2 18170 48202
   5 Locked QAM256 4 477.0 3.7 40.3 3071 8817
   6 Locked QAM256 5 483.0 3.5 39.8 400 1070
   7 Locked QAM256 6 489.0 3.3 39.9 4915 12728
   8 Locked QAM256 7 495.0 3.2 39.9 3917 10074
   9 Locked QAM256 8 501.0 3.1 39.9 4741 10428
   10 Locked QAM256 9 507.0 3.1 39.8 4084 7489
   11 Locked QAM256 10 513.0 2.9 39.7 3677 11478
   12 Locked QAM256 11 519.0 2.9 39.8 2937 9507
   13 Locked QAM256 12 525.0 2.8 39.7 2917 9295
   14 Locked QAM256 13 531.0 2.8 39.6 1526 3252
   15 Locked QAM256 14 537.0 2.9 39.7 4587 8128
   16 Locked QAM256 15 543.0 2.6 39.5 19140 26961
   17 Locked QAM256 16 555.0 2.4 39.1 14543 48603
   18 Locked QAM256 17 561.0 2.4 39.3 3161 7639
   19 Locked QAM256 18 567.0 2.3 39.3 4166 11133
   20 Locked QAM256 19 573.0 2.3 39.3 8318 29490
   21 Locked QAM256 20 579.0 2.3 39.3 1593 2920
   22 Locked QAM256 22 591.0 2.3 39.1 4880 8618
   23 Locked QAM256 23 597.0 2.4 39.2 4732 8768
   24 Locked QAM256 24 603.0 2.3 39.1 4387 9628
   25 Locked QAM256 25 609.0 2.0 39.1 3810 6910
   26 Locked QAM256 26 615.0 1.9 39.1 4212 8228
   27 Locked QAM256 27 621.0 1.9 39.1 7783 12851
   28 Locked QAM256 28 627.0 1.6 39.1 6488 16416
   29 Locked QAM256 29 633.0 1.6 39.2 6422 14339
   30 Locked QAM256 30 639.0 1.5 39.1 6719 14248
   31 Locked QAM256 31 645.0 1.4 39.1 6119 11658
   32 Locked QAM256 32 651.0 1.3 39.1 5208 10551
   33 Locked OFDM PLC 159 805.0 -1.3 35.1 331706592 29360829


   Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 5120 16.4 37.8
   2 Locked SC-QAM 2 5120 22.8 38.3
   3 Locked SC-QAM 3 5120 29.2 38.8
   4 Locked SC-QAM 4 5120 35.6 38.8
   5 Locked SC-QAM 5 2560 40.4 39.3




(edited)

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Update: Its been two days since the Comcast technician was at my house and declared 'everything looked great', since then the latency and packet loss errors have been occurring sporadically. Here are the router logs from my WAN Gateway monitor utility since then. Notice the majority of lost packets are on IPv4, the IPv6 connection has been pretty stable.

Router: pfSense

Modem: Motorola MB8600 (Docsis 3.1)

Comcast Gateway (IPv4): 73.24.196.1

Comcast Gateway (IPv6): fe80::29e:1eff:fe59:822

Apr 29 12:27:35   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13213us stddev 7461us loss 21%

Apr 29 12:27:58   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14007us stddev 8977us loss 19%

Apr 29 12:29:14   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 15309us stddev 8624us loss 21%

Apr 29 12:30:46   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 13040us stddev 7369us loss 14%

Apr 29 13:25:49   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13192us stddev 6927us loss 22%

Apr 29 13:26:04   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12367us stddev 6322us loss 15%

Apr 29 13:39:28   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 13761us stddev 7310us loss 13%

Apr 29 14:16:13   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 11554us stddev 5801us loss 21%

Apr 29 14:17:03   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 17274us stddev 23689us loss 19%

Apr 29 14:22:21   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 16698us stddev 10059us loss 21%

Apr 29 14:23:24   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14649us stddev 12736us loss 9%

Apr 29 14:27:20   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14083us stddev 8215us loss 21%

Apr 29 14:28:52   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12598us stddev 6569us loss 15%

Apr 29 14:46:10   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14151us stddev 8704us loss 21%

Apr 29 14:46:45   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 15686us stddev 9666us loss 20%

Apr 29 15:20:22   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13535us stddev 6845us loss 21%

Apr 29 15:21:07   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 15162us stddev 10428us loss 14%

Apr 29 15:45:11   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 17307us stddev 9636us loss 21%

Apr 29 15:46:18   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14269us stddev 7880us loss 13%

Apr 29 16:15:30   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14024us stddev 7021us loss 21%

Apr 29 16:15:56   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12758us stddev 6099us loss 15%

Apr 30 03:24:13   dpinger 1948      WAN_DHCP6 fe80::29e:1eff:fe59:822%igb0: Alarm latency 606387us stddev 1708476us loss 3%

Apr 30 03:25:16   dpinger 1948      WAN_DHCP6 fe80::29e:1eff:fe59:822%igb0: Clear latency 37815us stddev 71762us loss 0%

Apr 30 10:37:41   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 10185us stddev 3625us loss 21%

Apr 30 10:38:51   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14690us stddev 8564us loss 15%

Apr 30 10:38:58   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14403us stddev 8032us loss 22%

Apr 30 10:41:48   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 73360us stddev 120972us loss 11%

Apr 30 10:46:29   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14529us stddev 8187us loss 21%

Apr 30 10:49:28   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14618us stddev 8258us loss 18%

Apr 30 10:51:43   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14819us stddev 8114us loss 21%

Apr 30 10:52:25   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 16236us stddev 10791us loss 17%

Apr 30 10:56:27   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 80072us stddev 100595us loss 21%

Apr 30 10:57:16   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12283us stddev 11769us loss 15%

Apr 30 11:01:44   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 16441us stddev 9824us loss 21%

Apr 30 11:04:31   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 86110us stddev 123361us loss 7%

Apr 30 11:05:08   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 101494us stddev 129502us loss 21%

Apr 30 11:08:09   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14013us stddev 8504us loss 20%

Apr 30 11:08:11   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14181us stddev 8667us loss 21%

Apr 30 11:11:11   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 29363us stddev 43507us loss 16%

Apr 30 11:14:37   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 15364us stddev 8683us loss 21%

Apr 30 11:15:05   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 16210us stddev 12082us loss 19%

Apr 30 11:26:28   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 18364us stddev 10843us loss 21%

Apr 30 11:27:42   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 16344us stddev 9711us loss 19%

Apr 30 11:27:59   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 27640us stddev 26627us loss 22%

Apr 30 11:29:11   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12364us stddev 6115us loss 15%

Apr 30 11:32:54   dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 47060us stddev 70415us loss 21%

Apr 30 11:35:52   dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 11990us stddev 5863us loss 10%

(edited)

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Update: For the first time I experienced packet loss events over the weekend. The problem seems to be getting worse! Today at 5pm was particularly bad. See Gateway monitor logs below. I checked the modem event logs during the time that the packet losses were occurring and I noticed the repeating Notice/Warning: message sent/message timeout..

Also an anecdotal observation; the packet losses seem to be occurring at times of high wind gusts. Today was particularly windy.. Not sure if that has anything to do with it, but perhaps the wind is blowing the lines around and causing an intermittent connection. The majority of Comcast rigid coax lines are overhead on utility poles in my neighborhood...

Modem logs

   

17:25:02
Sun May 2 2021

 

Notice (6)

 

CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

   

17:25:06
Sun May 2 2021

 

Warning (5)

 

MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

(edited)

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Gateway Monitoring Logs

May 1 19:01:30    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13317us stddev 5663us loss 21%

May 1 19:02:21    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 14330us stddev 9339us loss 15%

May 2 09:21:46    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13189us stddev 7274us loss 21%

May 2 09:22:05    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 15217us stddev 19707us loss 20%

May 2 09:49:32    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13384us stddev 6817us loss 21%

May 2 09:50:13    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 13702us stddev 7078us loss 19%

May 2 10:03:56    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13353us stddev 7546us loss 21%

May 2 10:04:58    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12668us stddev 6826us loss 17%

May 2 10:07:49    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 12904us stddev 7531us loss 21%

May 2 10:09:05    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 12798us stddev 7069us loss 15%

May 2 17:11:20    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 14222us stddev 7863us loss 21%

May 2 17:11:33    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 13454us stddev 7573us loss 16%

May 2 17:13:19    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 86564us stddev 123692us loss 21%

May 2 17:32:45    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 16906us stddev 19519us loss 17%

May 2 17:38:24    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 16256us stddev 9685us loss 21%

May 2 17:41:02    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 13576us stddev 7372us loss 19%

May 2 17:42:16    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 13275us stddev 6544us loss 21%

May 2 17:42:37    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 13373us stddev 6596us loss 19%

May 2 17:46:53    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 15406us stddev 14914us loss 21%

May 2 17:47:52    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 18381us stddev 23465us loss 15%

May 2 17:50:58    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 18437us stddev 13464us loss 21%

May 2 17:51:12    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 18013us stddev 13403us loss 20%

May 2 17:51:23    dpinger 2263      WAN_DHCP 73.24.196.1: Alarm latency 19090us stddev 14017us loss 21%

May 2 17:52:09    dpinger 2263      WAN_DHCP 73.24.196.1: Clear latency 15005us stddev 8879us loss 16%

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Gateway Monitoring Logs for Monday 5/3/21 showing significant latency and packet loss in the late afternoon

May 3 16:41:55    dpinger 2263       WAN_DHCP 73.24.196.1: Alarm latency 17228us stddev 9754us loss 21%

May 3 16:42:09    dpinger 2263       WAN_DHCP 73.24.196.1: Clear latency 17353us stddev 10140us loss 16%

May 3 16:43:53    dpinger 2263       WAN_DHCP 73.24.196.1: Alarm latency 15027us stddev 8998us loss 21%

May 3 16:44:48    dpinger 2263       WAN_DHCP 73.24.196.1: Clear latency 13975us stddev 7269us loss 15%

May 3 16:59:20    dpinger 2263       WAN_DHCP 73.24.196.1: Alarm latency 12740us stddev 6634us loss 21%

May 3 17:00:25    dpinger 2263       WAN_DHCP 73.24.196.1: Clear latency 13211us stddev 6548us loss 15%

May 3 17:01:14    dpinger 2263       WAN_DHCP 73.24.196.1: Alarm latency 14979us stddev 10062us loss 21%

May 3 17:02:19    dpinger 2263       WAN_DHCP 73.24.196.1: Clear latency 13096us stddev 12202us loss 16%

May 3 17:03:30    dpinger 2263       WAN_DHCP 73.24.196.1: Alarm latency 15898us stddev 22046us loss 21%

May 3 17:04:07    dpinger 2263       WAN_DHCP 73.24.196.1: Clear latency 18060us stddev 30116us loss 18%

May 3 17:14:59    dpinger 2263       WAN_DHCP 73.24.196.1: Alarm latency 13735us stddev 7134us loss 21%

May 3 17:15:11    dpinger 2263       WAN_DHCP 73.24.196.1: Clear latency 13588us stddev 7619us loss 20%

May 3 17:44:13    dpinger 81456     WAN_DHCP6 fe80::29e:1eff:fe59:822%igb0: Alarm latency 540772us stddev 891000us loss 0%

May 3 17:44:13    dpinger 82186     WAN_DHCP 73.24.196.1: Alarm latency 524643us stddev 891563us loss 0%

May 3 17:45:14    dpinger 82186     WAN_DHCP 73.24.196.1: Clear latency 93532us stddev 321192us loss 1%

May 3 17:45:14    dpinger 81456     WAN_DHCP6 fe80::29e:1eff:fe59:822%igb0: Clear latency 106932us stddev 326469us loss 0%

May 3 17:50:49    dpinger 82186     WAN_DHCP 73.24.196.1: Alarm latency 14608us stddev 7229us loss 21%

May 3 17:51:35    dpinger 82186     WAN_DHCP 73.24.196.1: Clear latency 66341us stddev 96902us loss 13%

Official Employee

 • 

213 Messages

Hello, @, thank you for being so detailed and reaching out in our forum for help with your connection issues. I see you've been working with us and I'd like to continue where we left off to make sure we get to the bottom of things. In order to get started can you please send me a private message to Xfinity Support with your full name and full address by clicking the chat icon in the top right?

azdeltawye

Frequent Visitor

 • 

45 Messages

2 m ago

Update: The second Comcast technician showed up today to have a look. He spotted a rogue splitter that was installed on the utility pole near my house. Apparently the splitter was used by contractors who installed the new cable service to my neighbor, there were not enough ports available so they put in a three-way splitter. He said that was most likely the cause of the problem and put in a work order to have the two-port rigid coax tap block replaced with a four-port device. He seemed pretty confident that fix would resolve my packet loss issues.

I'll report back after the work order is complete. Fingers crossed...

Official Employee

 • 

273 Messages

Thank you for letting us know the results! That is great that the technician was able to find the possible issue. We keep an eye on any work orders that get submitted to our maintenance teams, and follow back up with you! Have a great weekend! 

EG

Expert

 • 

87.2K Messages

@azdeltawye

For curiosity, what do the signal stat numbers look like now ? 

azdeltawye

Frequent Visitor

 • 

45 Messages

1 m ago

Signal levels and error counts haven't changed much - see below.

I'll report back after the tap block has been changed out.

Connection Status    
   System Up Time 11 days 13h:19m:32s  
  
   Network Access Allowed  
  


   Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 21 585.0 2.0 38.9 299 581
   2 Locked QAM256 1 459.0 3.9 40.1 127 77
   3 Locked QAM256 2 465.0 3.8 40.0 2005 4010
   4 Locked QAM256 3 471.0 3.6 40.0 18609 49169
   5 Locked QAM256 4 477.0 3.6 39.9 3586 10245
   6 Locked QAM256 5 483.0 3.4 39.5 648 1960
   7 Locked QAM256 6 489.0 3.3 39.8 12570 24422
   8 Locked QAM256 7 495.0 3.2 39.8 4389 11008
   9 Locked QAM256 8 501.0 3.0 39.7 13120 20169
   10 Locked QAM256 9 507.0 3.0 39.6 4579 8420
   11 Locked QAM256 10 513.0 2.9 39.4 4633 14931
   12 Locked QAM256 11 519.0 2.8 39.4 4654 10451
   13 Locked QAM256 12 525.0 2.7 39.4 3357 10246
   14 Locked QAM256 13 531.0 2.7 39.4 1971 4184
   15 Locked QAM256 14 537.0 2.8 39.3 5621 11040
   16 Locked QAM256 15 543.0 2.5 39.1 19724 27888
   17 Locked QAM256 16 555.0 2.4 38.9 25827 53925
   18 Locked QAM256 17 561.0 2.4 39.1 7619 11700
   19 Locked QAM256 18 567.0 2.2 39.0 6007 17970
   20 Locked QAM256 19 573.0 2.1 38.9 11978 44198
   21 Locked QAM256 20 579.0 2.1 39.1 2021 3867
   22 Locked QAM256 22 591.0 2.1 38.9 5285 9579
   23 Locked QAM256 23 597.0 2.3 38.8 5224 9710
   24 Locked QAM256 24 603.0 2.1 38.8 5412 13262
   25 Locked QAM256 25 609.0 1.9 38.8 4342 7895
   26 Locked QAM256 26 615.0 1.8 38.8 4673 9675
   27 Locked QAM256 27 621.0 1.8 38.9 8332 14324
   28 Locked QAM256 28 627.0 1.5 38.9 7063 17481
   29 Locked QAM256 29 633.0 1.6 38.8 6873 15264
   30 Locked QAM256 30 639.0 1.4 38.8 7227 15724
   31 Locked QAM256 31 645.0 1.2 38.8 6532 12626
   32 Locked QAM256 32 651.0 1.2 38.9 5629 11522
   33 Locked OFDM PLC 159 805.0 -0.1 32.3 2067363880 149425390


   Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 5120 16.4 38.3
   2 Locked SC-QAM 2 5120 22.8 38.3
   3 Locked SC-QAM 3 5120 29.2 38.8
   4 Locked SC-QAM 4 5120 35.6 38.8
   5 Locked SC-QAM 5 2560 40.4 39.8


   Downstream Frequency Setting    

Official Employee

 • 

195 Messages

Thank you for keeping me posted. I will keep an eye on the maintenance referral and make sure we get this tested again once the new tap is in place.

EG

Expert

 • 

87.2K Messages

Us.....................................

azdeltawye

Frequent Visitor

 • 

45 Messages

1 m ago

So a week has passed since the last Comcast technician visit and nothing has changed:

  • Still experiencing random periods of packet loss and high gateway ping latency on a daily basis
  • The 2-port line tap and 'rouge' splitter are still up on the pole and have not been replaced

I periodically check the Xfinity app on my phone to see if there is any 'Scheduled Maintenance' planned for my area but nothing yet..

Can someone from Comcast check to see if an actual work order was put in to replace the line tap?

Trying to work from home under these conditions is frustrating to say the least...

azdeltawye

Frequent Visitor

 • 

45 Messages

1 m ago

Update: No resolution yet. I reached out Xfinity peer chat and inquired about the work order status. They replied and said that there were no pending work orders in my area and that they were unable to issue a new one. So we scheduled yet another technician visit since apparently they are the only ones who can write up a trouble ticket. This will be technician visit #3...

Packet loss issues still persist, and I have noticed a true correlation with the wind. Subsequently I have re-named the title of this thread to more accurately describe the issues I am seeing. There are hardly any packet losses observed when it is still, however when the wind gusts hit 20 mph or thereabouts, the latency increases and packets get dropped. This is primarily with IPv4 traffic, the IPv6 traffic seems to be unaffected.

Attached below is a screenshot from the IPv4 WAN Gateway monitoring utility in my router. This was today from 11am to 7pm. Today was very windy, wind gusts up to 30+ mph at times. For the 8 hour period it shows the average delay (latency) of around 11ms and average packet loss of 4%. Latency numbers tend to increase during periods of packet loss.

The screenshot below is the IPv6 monitor from the same time period showing 0% packet losses.

Official Employee

 • 

106 Messages

Thanks for providing that picture and information! We appreciate your patience while we work to find a resolution and will follow up with you as promised. Have a great weekend. 

azdeltawye

Frequent Visitor

 • 

45 Messages

1 m ago

Here is a picture of the areial tap block which my Comcast service is fed from. There are only two ports, yet three customers are connected, hence the splitter. Technician #2 was convinced that this was the root cause of my problem and said a different tap block with more ports needs to be installed. I guess we'll see what technician #3 thinks on Monday...

This comment was created from this reply
EG

Expert

 • 

87.2K Messages

Nah. That's not the issue. That tap and splitter are after a line extender / amplifier that can serve and does serve many many more subscribers farther down the line than just three. It was done out of convenience, time, and cost savings.

azdeltawye

Frequent Visitor

 • 

45 Messages

@EG 

Yeah I was skeptical myself, especially since my service is fed from the larger RG-11 coax on the left which is connected directly to the tap block. The splitter with the thinner RG-6 is for the other two customers.

Regardless, I think it would be best to have the correct tap block installed. Perhaps they will discover the real root cause while they are up there. I figure, the more eyes on the local system, the better...

azdeltawye

Frequent Visitor

 • 

45 Messages

1 m ago

Update: On Monday 5/24, technician  #3 came out to take a look. After his evaluation he performed the following actions:

  • Replaced a bad, non water-tight coax connector found on the neighbors service drop. He saw excessive FM noise ingress from this neighbor, and replacing this connector significantly reduced it.
  • Anchored loose coax cables for all three services drops (mine and two neighbors) to the pole to prevent movement during windy conditions.
  • Installed a MoCA filter on my service drop next to the ground bonding block on my house.
  • Called in for a 'modem watch' for my service.

I asked him what he thought about replacing the 2-port tap block (suggestion from Tech #2). He didn't think it was necessary because my signal levels were healthy and pointed out that my service was connected directly to the tap port and not attenuated by the splitter.

Overall he was very helpful and knowledgeable about the system. We'll see if this does the trick...

Official Employee

 • 

219 Messages

Hi there! I'm so happy to hear that you had a good experience with our technician. I'm confident this will do the trick. However, we have set a reminder to follow up with you on Monday to check in again and see how things are going. How does that sound? 

EG

Expert

 • 

87.2K Messages

Good luck with it !

.............

azdeltawye

Frequent Visitor

 • 

45 Messages

1 m ago

Update: Tuesday 5/25 not a single packet dropped! However it was a very calm day without any wind.  Wednesday 5/26 was a different story; slightly breezy in the late afternoon and evening. Packet losses started around 4:30 pm and continued through the evening. Back to the drawing board..

On a positive note; the packet losses I experienced on Weds were much lower than previous episodes. This might be a good sign...

(edited)

azdeltawye

Frequent Visitor

 • 

45 Messages

23 d ago

Update: My connection has been pretty stable since my last post, however there has been very little wind.. Today, even though it was still, I did experience some periods of packet loss; a small blip in the morning and a couple hour period in the afternoon. See below. The afternoon packet losses appeared to be caused by heavy use of my internet connection; during that time I downloaded about 17.5 GB and uploaded about 1.6 GB. You can see the delay (latency) jump up from around 10ms to over 30ms during this same time period.

New to the Community?

Start Here