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Intermittent Latency/Ping Spikes, Unstable Connection

Regular Visitor

Intermittent Latency/Ping Spikes, Unstable Connection

Hi, 

 

For about the past six months we've had intermittent issues with our internet that involve connection stability. This has ranged from high latency spikes where the internet doesn't go down completely, to full on connection loss. It's not a consistent issue, so it may go away for a month or two and then come back. We've had 3-4 technician visits that have really gotten nowhere, basically the tech shows up and says 'everything looks good!' and then leaves. My roommate recently purchased PingPlotter, so for our next tech visit we can actually have some data to show. I figured it may be helpful to post some modem event log/power setting information here to see if anyone has further insight that may help direct the tech visit. At this point, we think it's an issue with the line coming up to our apartment. The only noticable trending of instability comes with bad weather.

 

Thanks!

 

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 507000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode
 
 
 
 
Time Priority Description
2019-6-24, 20:46:19 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 20:25:35 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 19:55:23 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 19:40:15 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 19:25:08 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 18:54:57 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 18:09:42 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 17:39:30 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 17:24:21 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 16:08:58 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 15:38:46 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 15:23:38 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 15:08:31 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 14:38:18 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 11:58:35 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 11:58:11 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 11:58:11 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 11:57:25 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 11:57:24 Warning (5) Dynamic Range Window violation
2019-6-24, 11:57:03 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 10:52:48 Warning (5) Dynamic Range Window violation
2019-6-24, 10:52:14 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 10:37:07 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 10:31:53 Warning (5) Dynamic Range Window violation
2019-6-24, 10:20:53 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 10:16:38 Warning (5) Dynamic Range Window violation
2019-6-24, 10:06:55 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 09:57:31 Warning (5) Dynamic Range Window violation
2019-6-24, 09:55:53 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 09:51:46 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 08:23:57 Warning (5) Dynamic Range Window violation
2019-6-24, 08:23:55 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 08:12:28 Warning (5) Dynamic Range Window violation
2019-6-24, 08:11:05 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
2019-6-24, 07:21:07 Warning (5) Dynamic Range Window violation
2019-6-24, 07:21:02 Notice (6) WiFi Interface [wl0] set to Channel 11 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 07:07:03 Warning (5) Dynamic Range Window violation
2019-6-24, 07:05:57 Notice (6) WiFi Interface [wl0] set to Channel 6 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2019-6-24, 06:48:14 Warning (5) Dynamic Range Window violation
2019-6-24, 06:44:55 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=3c:37:86:08:d8:98;CMTS-MAC=00:01:5c:b2:9e:52;CM-QOS=1.1;CM-VER=3.0;
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 4 5120 Ksym/sec 17300000 Hz 43.5 dBmV
2 Locked ATDMA 3 5120 Ksym/sec 23700000 Hz 43.3 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 30100000 Hz 43.3 dBmV
4 Locked ATDMA 1 5120 Ksym/sec 36500000 Hz 43 dBmV
5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 16 507000000 Hz 8.3 dBmV 39.2 dB 1315 2977
2 Locked QAM256 12 477000000 Hz 8.8 dBmV 40.2 dB 1496 3923
3 Locked QAM256 13 483000000 Hz 8.5 dBmV 40.2 dB 1670 3384
4 Locked QAM256 14 489000000 Hz 8.4 dBmV 36.9 dB 1675 3478
5 Locked QAM256 15 495000000 Hz 8.1 dBmV 36.7 dB 1355 3098
6 Locked QAM256 17 513000000 Hz 8.2 dBmV 36.9 dB 1211 2673
7 Locked QAM256 18 519000000 Hz 8.1 dBmV 37.5 dB 1345 3061
8 Locked QAM256 19 525000000 Hz 8 dBmV 38.2 dB 1258 2259
9 Locked QAM256 20 531000000 Hz 7.9 dBmV 38.5 dB 1311 2889
10 Locked QAM256 21 537000000 Hz 7.9 dBmV 39 dB 1431 2179
11 Locked QAM256 22 543000000 Hz 7.8 dBmV 39.2 dB 1273 2243
12 Locked QAM256 23 549000000 Hz 7.6 dBmV 39.4 dB 1175 2231
13 Locked QAM256 24 555000000 Hz 7.4 dBmV 39.5 dB 1328 1895
14 Locked QAM256 25 561000000 Hz 7.3 dBmV 38.9 dB 1406 1811
15 Locked QAM256 26 567000000 Hz 7.2 dBmV 39.5 dB 1354 1865
16 Locked QAM256 27 573000000 Hz 7.2 dBmV 39.5 dB 1406 1845
17 Locked QAM256 28 579000000 Hz 6.7 dBmV 39.2 dB 0 0
18 Locked QAM256 29 585000000 Hz 6.8 dBmV 39 dB 0 0
19 Locked QAM256 30 591000000 Hz 6.8 dBmV 39 dB 0 0
20 Locked QAM256 31 597000000 Hz 6.4 dBmV 38.7 dB 0 0
21 Locked QAM256 32 603000000 Hz 6.1 dBmV 38.6 dB 0 0
22 Locked QAM256 33 609000000 Hz 6.2 dBmV 38.6 dB 0 0
23 Locked QAM256 34 615000000 Hz 6.2 dBmV 39 dB 0 0
24 Locked QAM256 35 621000000 Hz 6.2 dBmV 39 dB 0 0
Regular Visitor

Re: Intermittent Latency/Ping Spikes, Unstable Connection

PingPlotter_2019-06-24_21-56-18.pngFor some reason the image doesn't seem to be working, so here's a discord link to the pingplotter image. https://cdn.discordapp.com/attachments/244670173544448001/592926232203624453/PingPlotter_2019-06-24_...

Expert

Re: Intermittent Latency/Ping Spikes, Unstable Connection

Is this with a WiFi connection ? If so, for a test, does a computer hardwired directly to the router / gateway device with an ethernet cable have the same problem ?



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Regular Visitor

Re: Intermittent Latency/Ping Spikes, Unstable Connection

This is an ethernet connection. We have some wifi-connected devices but they are used minimally.

Expert

Re: Intermittent Latency/Ping Spikes, Unstable Connection

Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) 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 can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Official Employee

Re: Intermittent Latency/Ping Spikes, Unstable Connection

MDaddario28, thanks for taking the time to let us know about your connectivity issues and posting your modem logs here. Appreciate it! I'd be more than happy to take a look into what is causing these spikes and drops. We'll check at and outside your premise to get to the bottom of this. Please send me a private message with your full name for assistance. 

 

Ken


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Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
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