Community Forum

Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

John_H3
Contributor

Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Hi All,

 

I am reaching out to see if someone can help me with my internet connection. I am experiencing huge issues. My internet connection keeps randomly dropping every 10 minutes, or so. It stays down for 1 to 2 minutes (usually, but it can stay down for longer, up to 5-10 minutes), then comes back. As an example, in the last 6 hours, it dropped 34x times, being down for almost 25% of the time. I need to work from home, vpn, t-calls, etc. and this is just not working. Unfortunate.

 

Some background. I have moved to a new apartment ~9 months ago. Internet has been working just fine until about ~6-7 weeks ago. Then the intermitted connection problem showed up.

 

My equipment. I have been using for the last ~6 years an Arris sb6141 (modem) with an Apple AirPort Extreme (router). I talked to Xfinity customer service and they blamed right away my modem/router. I was not very convinced (just because cause the combo has been working fine for years until few weeks ago), however, following their recommendation, I got a new modem from the list of Xfinity recommended devices (Netgear CM600), and a new router, too (Google Nest). Unfortunately, the problem remained.

 

Xfinity Technician. I contacted back Xfinity support and then they decided to send a technician to check my building and apartment. The technician was here, and checked everything in both the basement and apartment, installed new filters, replaced switches, etc. He did not found anything wrong on my side, however, he could not solve the problem, but he acknowledged the intermitted issue.

 

He then sent it another ticket to have someone to come and check the post next to my apartment and connection getting to my building. They were supposed to be here yesterday morning, however, unfortunately, no-one showed up yet.

 

I will post below logs from my modem. I am hoping someone here can give some wise insight about what I should do next. Having to work from home and having internet going down every 10 mins is like to having an internet connection 😐

 

Thanks everyone in advance, ~JH

 

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

this is modem connection - as you can see, power and SNR values are looking good, however a lot of 'uncorrectables' - let me know if I am missing something here

 

Starting Frequency
 
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 459000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enable BPI+
IP Provisioning Mode Honor MDD IPv6 only
 
Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 1 459000000 Hz -1.4 dBmV 40.1 dB 21196 9113
2 Locked QAM256 17 555000000 Hz -1.2 dBmV 40.0 dB 11373 4681
3 Locked QAM256 18 561000000 Hz -1.2 dBmV 39.9 dB 11407 4538
4 Locked QAM256 19 567000000 Hz -1.3 dBmV 39.9 dB 11095 4053
5 Locked QAM256 20 573000000 Hz -1.7 dBmV 39.7 dB 11187 4788
6 Locked QAM256 21 579000000 Hz -1.6 dBmV 39.8 dB 10776 3621
7 Locked QAM256 22 585000000 Hz -1.6 dBmV 39.7 dB 10243 3783
8 Locked QAM256 23 591000000 Hz -1.6 dBmV 39.7 dB 9813 4100
9 Locked QAM256 24 597000000 Hz -1.7 dBmV 38.8 dB 9318 3455
10 Locked QAM256 2 465000000 Hz -1.4 dBmV 40.0 dB 19247 7606
11 Locked QAM256 3 471000000 Hz -1.5 dBmV 40.0 dB 17291 7749
12 Locked QAM256 4 477000000 Hz -1.7 dBmV 39.9 dB 18070 7455
13 Locked QAM256 5 483000000 Hz -1.7 dBmV 39.9 dB 17662 7142
14 Locked QAM256 6 489000000 Hz -1.7 dBmV 40.0 dB 17511 7258
15 Locked QAM256 7 495000000 Hz -1.7 dBmV 39.9 dB 15374 6632
16 Locked QAM256 8 501000000 Hz -1.7 dBmV 39.8 dB 15121 5947
17 Locked QAM256 9 507000000 Hz -1.9 dBmV 40.8 dB 0 0
18 Locked QAM256 10 513000000 Hz -2.2 dBmV 40.8 dB 0 0
19 Locked QAM256 11 519000000 Hz -2.1 dBmV 40.8 dB 0 0
20 Locked QAM256 12 525000000 Hz -2.1 dBmV 40.8 dB 0 0
21 Locked QAM256 13 531000000 Hz -1.8 dBmV 40.8 dB 0 0
22 Locked QAM256 14 537000000 Hz -1.8 dBmV 40.8 dB 0 0
23 Locked QAM256 15 543000000 Hz -2.0 dBmV 40.8 dB 0 0
24 Locked QAM256 16 549000000 Hz -1.8 dBmV 40.8 dB 0 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 5 5120 Ksym/sec 36500000 Hz 42.3 dBmV
2 Locked ATDMA 6 5120 Ksym/sec 30100000 Hz 41.8 dBmV
3 Locked ATDMA 7 5120 Ksym/sec 23700000 Hz 42.0 dBmV
4 Locked ATDMA 8 5120 Ksym/sec 17300000 Hz 42.5 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
 
Current System Time: Wed May 27 08:17:57 2020
System Up Time: 15:54:56
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

And this is the event log from the modem

 

Time Priority Description
2020-05-27, 07:06:22 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 07:05:50 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 07:05:49 Warning (5) Dynamic Range Window violation
2020-05-27, 07:05:37 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 03:45:03 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 03:45:03 Warning (5) Dynamic Range Window violation
2020-05-27, 01:16:36 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 01:16:23 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 01:16:03 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 01:16:03 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 01:01:55 Warning (5) Dynamic Range Window violation
2020-05-27, 01:01:54 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 00:00:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 00:00:21 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:59:53 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:59:44 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:49:04 Warning (5) Dynamic Range Window violation
2020-05-26, 23:48:56 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:28:22 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:27:17 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:27:06 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:26:53 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:26:26 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 23:25:53 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 22:41:22 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 22:38:06 Warning (5) Dynamic Range Window violation
2020-05-26, 22:38:05 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:48:49 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:48:49 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:48:16 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:48:04 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:46:07 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:45:59 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:45:34 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:25:06 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:24:41 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:24:34 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:24:01 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:23:29 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-26, 19:23:21 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

could it be that it's the ISP  that drops the connection and not my router/modem?

EG
Expert

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

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.

You should get a reply here in your topic. Good luck !



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!
ComcastChe
Official Employee

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Hi @John_H3

 

Thank you for posting and welcome to the Xfinity Forum! I agree with @EG. I'd be more than happy to investigate your issues a little more to see what we need to do to make this right. To get started, please send me a private message with your first and last name. To send a private message, click on "ComcastChe" and then click send a message. 


I am an Official Comcast Employee.
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.
Was your question answered? Mark the post as Best Answer!
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Thank you so much for your help EG! I would be glad to be working with Xfinity tech support team and figure our the problem

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Great - I will get in touch through private messaging

p.s., I hope we can improve it soon - working from home with a connection dropping multiple times an hour is literally killing me

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

and this are the log from this afternoon - it has been really bad

 

Time Priority Description
2020-05-27, 17:42:24 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 17:01:04 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 17:00:19 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 16:58:48 Critical (3) No UCDs Received - Timeout;;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:58:31 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:58:27 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 16:57:45 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:57:39 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 16:56:49 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:56:48 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:56:15 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:52 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:50 Critical (3) No UCDs Received - Timeout;;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:33 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:32 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:31 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:19 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:18 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:18 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:55:15 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-27, 16:54:27 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:54:19 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:53:46 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:52:27 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:51:29 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:50:09 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:50:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:49:41 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:49:40 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:49:35 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:48:48 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:48:45 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:45:19 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:44:21 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:43:23 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:43:21 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:42:49 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:41:29 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-27, 16:40:31 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

... and these are the results from StarTrinity Continuous Speet Test (it is an image, it would need to be approved by a moderator, I think).

 

text summary for the last 2 hours:

-1h 2m uptime (58%)

-45 m downtime (42%)

-61x downtime(s)

 

 

Untitled.png

 

ComcastChe
Official Employee

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

I'm done testing on my end. Upon checking your node, I was able to confirm there are some Upstream issues being reported in your area, but it has not yet been confirmed an outage or known issue. Your signals are all green as well, but I do see a lot of T3/T4 timeouts. Let's see if the troubleshooting I completed will help any. 

 

Can we please monitor this over the next 24-hours and let me know if there is a change on your end? If the issues are still present as of tomorrow, I will see if I am able to get a tech out again so we can get this escalated to the maintenance team, for investigation of possible issues at the node or on your line. 

 

 


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John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Hi ComcastChe,

 

thank you for working on it and for conferming Upstream issues and T3/T4 timeouts.

 

I will be working from home tomorrow all day, and I will be in front of my PC. Let's see how it goes and I will report it here. Hope we can soon find a solution.

 

Have a good evening and I will be in touch.

Thank you, ~JH 

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Hi, good morning - unfortunately I keep having huge issues. I began working this morning around 7 am, connection already dropped >50 times! I need to work from home - this is like not having an internet connection: cannot make a work t-call, the longest internet is up is ~10 minutes 😞

 

Let me know, what next steps are. Thanks everyone again for help and support!

 

this is snapshot of the last 20 minutes: 3 downtimes

Untitled.png 

some more modem logs:

Time Priority Description
2020-05-28, 09:06:38 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:54:22 Warning (5) Unicast DSID PSN startup error
2020-05-28, 08:54:00 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-05-28, 08:53:47 Critical (3) No UCDs Received - Timeout;;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:53:37 Warning (5) Lost MDD Timeout;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:53:30 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:53:27 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:53:09 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:53:02 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:52:53 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:52:21 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:52:03 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:51:56 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:51:51 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:51:29 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:51:17 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:50:41 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-05-28, 08:50:33 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:50:25 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:50:04 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-28, 08:49:38 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:49:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:49:19 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:49:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:48:38 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:48:36 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:48:18 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:48:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:47:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:47:46 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:47:19 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:46:46 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:46:39 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:46:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:45:59 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:45:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:45:20 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:45:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:44:39 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-28, 08:44:37 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

 

Time

Priority

Description

2020-05-28, 07:33:55

Warning (5)

Dynamic Range Window violation

2020-05-28, 07:33:54

Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

2020-05-28, 07:17:33

Notice (6)

Honoring MDD; IP provisioning mode = IPv6

2020-05-28, 07:17:27

Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;

2020-05-28, 07:17:23

Critical (3)

No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;

2020-05-28, 07:17:13

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

2020-05-28, 07:15:42

Critical (3)

Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

2020-05-28, 07:15:15

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

2020-05-28, 07:15:03

Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

2020-05-28, 07:14:42

Critical (3)

Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Can someone from xfinity please get back to me? Thank you
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

to add more info,

 

in the last 80 minutes today (5/28), I have had 8 downtimes

 

my internet was down:

- at 5:14 pm for 11m 45s

- at 5:26 pm for 20m 36s

-at 17:58 for 1m 3s

- at 18:14 for 5m37s

-at 18:24 for 4m22s

 

overall, internet is being down more than 50% of the time

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Good morning - another update

 

 

 suggested to double check all connections, following the indications below (blue). 

 

Inspect cabling
Inspect coax lines:
 • For extreme bends or kinks.
 • For abrasions or cuts.
 • For broadband compliance. The coax should be RG6.
 • For proper fasteners. Coax cable should not be stapled, particularly at regular intervals. 
 • Excess cable. Coax lines should be a short as possible.

 

Inspect Ethernet cables 
It's fairly uncommon for Ethernet cables to fail, but it does happen. Kinks and connector failures are the most common culprits. Ethernet cables should be Cat 5e or Cat 6. 
 
Check F-Connectors 

  • Ensure connectors are tightened properly, corrosion-free and that the center conductor appears shiny.
  • Connectors must be compression fittings, crimped fittings are not acceptable. 
  • Connectors on the backs of faceplates are a common failure point, don't forget to check them too. 
EG
Expert

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

FWIW, the past two days may have been .@ComcastChe's days off. I'm going to re-escalate this.



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!
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Thank you EG - I really appreciate your help. It would be great if I could get some more attention from Comcast to my problem. Best, ~JH

EG
Expert

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Your welcome !



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!
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

One more piece of update for Comcast.

 

Unfortunately, all my cable maintainance mentioned above did not improved the situation. Internet keep dropping very frequently (an example of modem logs from this morning in the table below).

 

I started to use StarTrinity Continuous Speet Test and have monitored uptimes vs downtimes for the last 24h. During the night, downtimes only occurred 3x times for no more than a few minutes, however, between 8 am in the morning and 12 pm today, I already had more than ~25 downtimes (one every 10 minutes) . This seems to suggest 'comcast upstream issues' rather than cable connections in my home - I do not see how my cables are decent at night, bad during the day 🙂

 

To summarize all posts above:

  • I never had a problem until ~5 weeks ago.
  • Since then, my internet connection during the day drops every 5-10 mins, stays down for 2-3 minutes (but sometimes 10-20 minutes, or more). Internet during the day is down ~50% of the time 😮
  • I have replaced my modem and router ~2 weeks ago. Did not help.
  • After that, I had two Xfinity technicians to check my basement and apartment. We checked all cables, couplers. We have removed all splitters, and installed new filters. We did not found anything wrong. It did not help
  • Following ComcastChe reccomendation, I have checked myself one more time all connections (I am an eletrical/biomed engineer, pretty familiar with coax cables, and similar components). I even opened the wall plugs. I replaced old couplers with new couplers.  Did not see anything wrong and nothing helped.
  • I have relocated the modem position in my apartment and try to use 3x different wall plugs. Did not make any difference.
  • I have replaced the coax cable going from wall to modem. Did not help.
  • I have replaced all ethernet cables and have moved all devices to wifi, except for my laptop being connected directly to my router. Did not help.
  • I have tried to connect the laptop directly to the modem with etherned to see if there was any different. Connection keeps dropping anyway.

 

I am really hoping to hear from Comcast soon. I am working from home, and basically I do not have an working internet connection.

 

Modem logs for the last 15 minutes:

Time Priority Description
2020-05-29, 10:05:09 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:05:09 Warning (5) Dynamic Range Window violation
2020-05-29, 10:04:36 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:04:36 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:04:03 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:02:38 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:01:29 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:01:04 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:00:56 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:00:56 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:00:36 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 10:00:24 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 09:58:34 Warning (5) Dynamic Range Window violation
2020-05-29, 09:58:30 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 09:55:51 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 09:55:51 Warning (5) Dynamic Range Window violation
2020-05-29, 09:51:38 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 09:51:38 Warning (5) Dynamic Range Window violation
ComcastJoeTru
Official Employee

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Hi John_H3. Apologies your internet issues continue. I can assist with further troubleshooting. Please send me a private message and include your full name so I can assist you. 


I am an Official Comcast Employee.
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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John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Thank you - will send a pm in a minute

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Hi All,  wanted to give another update. ComcastJoeTru did some more remote debugging, but unfortunately no luck. In the last 2 hrs connection dropped > 20 times again, being down ~50% of the time

 

many many T3 and T4 errors in my modem logs:

 

Time Priority Description
2020-05-29, 19:09:50 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:09:47 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:09:41 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:09:14 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:08:54 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:49:51 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:49:07 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:49:07 Warning (5) Dynamic Range Window violation
2020-05-29, 18:48:40 Warning (5) Dynamic Range Window violation
2020-05-29, 18:47:26 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:44:09 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:43:41 Warning (5) Dynamic Range Window violation
2020-05-29, 18:43:37 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:43:36 Warning (5) Dynamic Range Window violation
2020-05-29, 18:43:17 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:40:50 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:40:28 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:40:17 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:37:19 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-05-29, 18:37:13 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.0;CM-VER=3.0;
2020-05-29, 18:37:03 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:35:33 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:35:32 Warning (5) Dynamic Range Window violation
2020-05-29, 18:35:13 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:35:12 Warning (5) Dynamic Range Window violation
2020-05-29, 18:34:52 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:21:59 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:20:58 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:20:54 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:20:47 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:20:14 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:20:07 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:19:54 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 18:19:34 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

 

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

And a ton more 😞

Time Priority Description
2020-05-29, 20:23:23 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:22:18 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:21:43 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:20:38 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:20:04 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:18:59 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:18:24 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:17:19 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:16:44 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:15:39 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:15:04 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:13:59 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:13:24 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:12:19 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:11:32 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:10:59 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:10:12 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:09:40 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:08:52 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:08:20 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:08:12 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:07:40 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:07:32 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:07:00 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:06:12 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:05:40 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:04:45 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:04:45 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:04:45 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:04:05 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:04:05 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 20:04:05 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:57:38 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:57:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:56:39 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:56:27 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:56:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:55:39 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:55:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-05-29, 19:54:39 Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;

 

 

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 5 483000000 Hz -0.6 dBmV 40.2 dB 12389 1480
2 Locked QAM256 17 555000000 Hz -0.5 dBmV 40.2 dB 7310 1480
3 Locked QAM256 18 561000000 Hz -0.5 dBmV 40.1 dB 7248 1603
4 Locked QAM256 19 567000000 Hz -0.7 dBmV 40.1 dB 6688 1676
5 Locked QAM256 20 573000000 Hz -1.2 dBmV 39.9 dB 6845 1283
6 Locked QAM256 21 579000000 Hz -1.1 dBmV 39.9 dB 6305 1562
7 Locked QAM256 22 585000000 Hz -1.0 dBmV 39.9 dB 5906 1512
8 Locked QAM256 23 591000000 Hz -1.0 dBmV 39.8 dB 5609 1752
9 Locked QAM256 24 597000000 Hz -1.2 dBmV 38.8 dB 5373 1400
10 Locked QAM256 1 459000000 Hz 0.1 dBmV 40.6 dB 17108 1733
11 Locked QAM256 2 465000000 Hz 0.1 dBmV 40.6 dB 14612 1614
12 Locked QAM256 3 471000000 Hz -0.1 dBmV 40.4 dB 15426 1504
13 Locked QAM256 4 477000000 Hz -0.4 dBmV 40.3 dB 16446 1477
14 Locked QAM256 6 489000000 Hz -0.7 dBmV 40.2 dB 11181 1346
15 Locked QAM256 7 495000000 Hz -0.8 dBmV 40.2 dB 8583 1263
16 Locked QAM256 8 501000000 Hz -0.7 dBmV 40.1 dB 9197 1596
17 Locked QAM256 9 507000000 Hz -0.9 dBmV 41.1 dB 0 0
18 Locked QAM256 10 513000000 Hz -1.2 dBmV 40.9 dB 0 0
19 Locked QAM256 11 519000000 Hz -1.1 dBmV 40.9 dB 0 0
20 Locked QAM256 12 525000000 Hz -1.1 dBmV 40.9 dB 0 0
21 Locked QAM256 13 531000000 Hz -0.7 dBmV 41.2 dB 0 0
22 Locked QAM256 14 537000000 Hz -0.9 dBmV 40.8 dB 0 0
23 Locked QAM256 15 543000000 Hz -1.2 dBmV 40.8 dB 0 0
24 Locked QAM256 16 549000000 Hz -1.1 dBmV 40.8 dB 0 0
CCAndrew
Diamond Problem Solver

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Keep communicating with @ComcastJoeTru privately he’s the ticket to an eventual fix.

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John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Thank you CCAndrew. All right. I will keep talking to ComcastJoeTru
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

24 hr have gone by and have not heard anything from anyone - in the last 3 hrs, internet has been up for no more than 20 mins.

 

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MugglePuggle
New Poster

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

I have read your thread and I am having an identical problem. An Xfinity technician came to my house today to check my outside wires and he left it in a state where the box is undone and laying on my yard and all of the wires are exposed. (see pic)  When I used the chat feature to ask what was my status, they told me that a technician was not scheduled to be at my house (wrong) and they could do a "virtual" assessment of my system due to Covid. I also work from home and discovered that my cellphone hotspot works for my needs. It is awful that I have to pay $230 a month and do not have reliable internet. I will be following to see how your situation is resolved. IMG_7365.jpeg

JaneDaCustomer
New Poster

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

I’m having the same issue. Ever since some technician came to fix a “noise” problem coming from house specifically, it’s been dropping like crazy. To the point I’m completely out of service in the afternoon. Absolutely insane when I’m paying over $230 for this service. Constant outages, intermittent service, etc. No cell provider has a strong enough signal to have a hotspot from them. So getting an additional device is pointless. Also, why should I have to do that when I’m paying for the top tier speed. So if I don’t have WiFi (subsequently WiFi calling), I don’t have access to anyone without walking down the street. On top of that you call customer service and they're telling you reboot your modem. Cmon...how many times a day should a customer have to do this??? I hope someone comes up with a solution because what it sounds like is that the service is saturated with everyone being at home and they’re not being honest about it.
JaneDaCustomer
New Poster

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

In addition, I have wires exposed on the side of my home as well. But 3 “technicians” have been out and no one had the common sense to do cable management and place things as they should be. Cover the wires up. As I stated, someone was out here recently. As recent as April. Ridiculous.
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Thank you for posting. Now I know I am not crazy and not the only one with this issue. I feel like I need to state it again: I am not talking about a few drops a day, but one every 5 minutes making me impossible to work at home.

 

Found a couple of threads on the same topic that are quite interesting:

https://forums.xfinity.com/t5/Your-Home-Network/Intermittent-dropped-internet/td-p/3254091/page/2

https://forums.xfinity.com/t5/Your-Home-Network/Intermittent-dropped-connection-RESOLVED-SEE-BOTTOM-...

 

I need to post here again, hoping to get more attention from Comcast. After an initial attempt, I got back in pm to both ComcastTruJoe and ComcastChe, but I have not heard anything back. Is there a better way to reach out asking for help? I do understand individual technicians might be out for the weekend, or other. From one of thoose threads, it seems like I may want to reach out to Comcast_Support instead - is this a better practice?

 

I also have talked to the customer service on the chat Friday morning. I was told that my issue was escalated and that someone would get in touch with me in 24h, it never happened.

 

I then talked to one of my two neighbors (we live in a three family building). Surprise: he experiences the same issue. I have learnt that independently from what I am doing here, he also got a technician to check the building ~two weeks ago. Nothing was found. Te technician said he was going to put a ticket in, and that in a few days someone from Comcast would have called and come to check the connection getting to our building and surrounding ones. Well, this never happened, too.

 

At this point, it is probably futile for me to post here some more modem logs, but I can report 10s thousands uncorrectable for the modem download channels 1-16, and t3/t4 every other minutes.

 

As I said, I am posting again, as I am hoping to get attention from Comcast and get some more dedicated resources to fix my internet connectivity, trying to get an internet connection I can actually use. Thanks 

EG
Expert

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

I don't know if it will help, but guess what, I'm going to re-escalate this for the second time.



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fishdr58
Regular Visitor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

I'm experiencing the same exact issues. I've had countless techs here and they've replaced literally everything...I started with my own modem/router setup and they blamed that so I switched to renting their equipment, but to no avail. I was also told by one helpful tech that there was an upstream issue with one of the nodes up the road from me, but nothing was ever done. It's honestly unbearable, but there are no other ISPs in our area. If you figure anything out, please share!

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

yes - will do! They made me replace modem AND router, as well. A waste of my $$ and of my own time. ComcastChe later mentioned 'upstream issues', but have not heard anything from anyone in days, now. I will keep you posted here. Hope that discussing publicly can help other people with the same issue.

 

 

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

another 24h went by, and guess what? I still have not heard from anyone.

 

meanwhile, found an interesting read: https://pickmymodem.com/cable-modem-t3-and-t4-timeouts-error-messages-and-how-to-fix-them/

  • T3 Timeouts are typically caused by Upstream Noise causing Ranging Requests to not be clearly received by the CMTS. T3 problems can often be intermittant in nature as they may be the result of noise originating in any part of the plant that shares the same line card at the CMTS with the subscriber impacted. 
  • T4 Timeouts result when a CM does not receive a Station Maintenance Opportunity in which to transmit a Ranging Request within the T4 timeout period which is approximately 30 seconds. T4s typically result from an impairment in the downstream. As they take an interruption in connectivity for 30 seconds to occur and trigger a reset, T4s can be indicative of major faults like damaged drops, or mainline congestion but can also occur from maintenance work in the plant or at the headend as well. A low T4 count may be indicative only of repeated maintenance operations while a high T4 count may represent a severe plant or drop impairment.

 

The log below is from this morning during a futile attempt of making a work T-call (had to switch over my data plan from a different provider...) - a T4 error every minute or so... when will Comcast pay attention to my issue and give me a clear answer? Thanks

 

Time Priority Description
2020-06-01, 09:15:48 Warning (5) Dynamic Range Window violation
2020-06-01, 09:15:38 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:15:05 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:14:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:14:25 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:13:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:13:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:12:59 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:12:27 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:12:25 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:12:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:11:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:11:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:10:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:10:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:09:58 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:09:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:08:59 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:08:26 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:07:39 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:07:10 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:07:10 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:07:10 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:07:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:06:39 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:06:10 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:06:06 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:05:19 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:04:51 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:04:46 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
2020-06-01, 09:03:46 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:c1:69:40;CMTS-MAC=18:8b:9d:d4:08:ec;CM-QOS=1.1;CM-VER=3.0;
ComcastJoeTru
Official Employee

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

We're sorry for our delay in getting back with you, John_H3. We want to help get your issues resolved as soon as we can. I have responded to your recent Private Messages. Thanks for your understanding. 


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John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

An update for other people reading this thread, who may have interest.

 

The problem is not solved. A Xfinity technician came here ~3 weeks ago, checked all cables and connection, but has not find any issue or solved the problem either.

 

The Xfinity customers support is telling me that they will need to send out someone else to check connections again, however due to covid this is not possible at this time. I have been unable to use my internet connection for more than 12 weeks now.

DirtyPatriot
New Poster

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

basically if you have a gig plan and dont use a xfinity supplied modem/router they throttle and crush your speeds. its fixed by firmware update only and they refuse to do it. this has been ongoing for almost a year. xfinity just says the issue is something else and will keep sending you techs. these posts pop up evryday. 

John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

All right - some new info about my issue I hope people reading this post may find of interest

 

my internet connection is still unusable - talked to the customer service for the ~10th time

 

I have been redirected to what Comcast calls the 'Advance Repair Team', this is what they said and done: 'I am done with the check and the system identified the modem is online however, it also detected signal issue that is causing the intermittent connectionI am going to complete update and refresh here in our backend for the service and I will be sending a push signal to the modem. I have did a refresh on the bootfile from the backend and corrected the signal issue. If in case the issue persist, we will set up a technician visit for you.'

p.s., not totally sure what this means exactly - if someone can explain, it would be appreciated.

 

In any event, unfortunately, the issue did not go away. So they have scheduled a third technician to come visit my building tomorrow. Let's see if this solves my internet connection, which I have not been able to use since ~April

bexcaducea
New Poster

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Replying so I can follow thread.
OP, I feel your pain and am thankful I don't work from home or game competitively online. We pay for Blast! (200mbps). Speed checks used to be 20mbps down and 12 up on a hardwired connection from desktop to modem. Figured it was our old combo modem/router. Got a new modem (Arris 1.4) and router (wavlink3000) and the speed test is 30mbps down and 10-12 up. No change. I've spent several hours on various days beating my head against a wall erm I mean *communicating* with offshore tech support. Was promised a tech visit: nope... it was never even scheduled. That afternoon I "karen-ified" myself a demanded a supervisor. The supposed supervisor again offered a tech visit (this Thurs), but I don't see any scheduled appts on my account.
Spouse's brother registers 200+mbps down and 10-15 up on his own modem and separate linksys router.
How does one get a Comcast employee to actually help?

@DirtyPatriot : any suggestions? can the firmware be updated from elsewhere?
John_H3
Contributor

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

A last update which hopefully is the end of the story. It seems that I was finally able to pin-down my internet issue. It seems that the problem was about a sub-optimal connection outside my building. I had 2x technicians coming here a few weeks ago, checking all inside connections without finding an issue. Did not help, so I got a third technician to came out 2 days ago. This time I asked him to check the connections outside the building. He remade the termination for the cable that from a splitter from a Comcast central unit is getting to my building an apartment and further tighten all other connection. Since then, 72 hours have gone by and have not had a single T3-T4 error, yet - looks promising. Hope it stays this way

 

The only advice from this story I have for people with the same issue is to be persistent, get technicians out, give them as many details you need, try to understand yourself how wiring is done for you inside and outside your building, and keep going until the issue is fixed 🙂

 

It has been real painful for me not having an internet connection for the last 3 months, and not always easy to deal with the customer support, but at last the third technician coming out was a really good guy willing to help and listen, and together we figured out how to solve the issue.

 

If the problem will come back, I will open a new post, but hopefully I will be good for a while now...

EG
Expert

Re: Xfinity 100 Mbps connection keeps dropping (intermittent) multiple times per hour

Thanks for posting that info. Glad that it finally got straightened out ! Hope things hold up for you ! Good luck ! Now closing this thread.



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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.
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