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Visitor

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4 Messages

Wed, Aug 4, 2021 9:00 PM

Intermittent outages for months with T3 timeouts between two different modems

For the past couple of months I've been having random internet outages throughout the day and night. Sometimes usually a minute or two but can go as long as ten minutes. Comcast reports no outages whenever this happens. I replaced my Motorola MB8600 with an Arris S33 but the issue remained. A Comcast technician came out and said I had a good, strong connection but replaced some older components in the exterior box to see if that would help. I continued to have internet outages a few hours after he left.

I called support (after chat told me I'd receive a priority call that never came) and went through the usual troubleshooting steps with the support agent (reboot modem, router, etc. stuff I've done a dozen times during the last couple of months).

And, just to vent a little because I'm pretty frustrated after that call, they insisted the issue was with my router (a Ubiquiti Edgerouter Lite 3) because it was in the basement despite me telling him the router has no wi-fi, I have independent access points spread through my house, my outages also affect the many devices I have connected by ethernet, my internal network works fine during the outages, and the cable modem logs of the T3 errors line up with every outage. He insisted I contact my router OEM to rule it out. I relented and said I would but I'd like him to make a note on my account so I can avoid the hour of basic troubleshooting when I call back up to get it escalated. He told me all calls have notations and then hung up on me.

Here's a copy of my latest cable modem logs:

Date Time Event Level Description
4/8/2021
11:44:45
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;
4/8/2021
11:44:48
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;
4/8/2021
11:44:49
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;
4/8/2021
11:44:50
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;
4/8/2021
11:44:53
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;
4/8/2021
11:44:53
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;
4/8/2021
11:44:56
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;
4/8/2021
11:44:57
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;
4/8/2021
11:45:02
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;
4/8/2021
11:45:38
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;
4/8/2021
11:45:57
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;
4/8/2021
11:48:22
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;
4/8/2021
11:48:30
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;
4/8/2021
11:48:51
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;
4/8/2021
11:48:56
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;
4/8/2021
11:49:00
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;
4/8/2021
11:49:02
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;
1/1/1970
00:00:17
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;
1/1/1970
00:00:30
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;
1/1/1970
00:00:45
6 Honoring MDD; IP provisioning mode = IPv6
4/8/2021
12:52:24
6 DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
12:52:43
6 CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
12:53:21
6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
12:54:00
6 CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
13:17:50
3 Successful LAN WebGUI login from 76.27.32.140 on 21/08/04 at 1:17 PM.
4/8/2021
13:32:33
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;
4/8/2021
13:33:18
6 CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
13:49:54
6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
13:50:44
6 CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
13:51:36
6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
13:51:50
6 CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
4/8/2021
13:53:24
3 Successful LAN WebGUI login from 76.27.32.140 on 21/08/04 at 1:53 PM.
And here's my status page:
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 579000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
28 Locked QAM256 579000000 Hz -5 dBmV 37 dB 704 706
4 Locked QAM256 423000000 Hz -3 dBmV 38 dB 688 881
5 Locked QAM256 429000000 Hz -3 dBmV 38 dB 828 966
6 Locked QAM256 435000000 Hz -3 dBmV 38 dB 687 807
7 Locked QAM256 441000000 Hz -3 dBmV 38 dB 672 796
8 Locked QAM256 447000000 Hz -3 dBmV 38 dB 890 1036
9 Locked QAM256 453000000 Hz -3 dBmV 38 dB 638 729
10 Locked QAM256 459000000 Hz -2 dBmV 38 dB 723 749
11 Locked QAM256 465000000 Hz -3 dBmV 38 dB 858 857
12 Locked QAM256 471000000 Hz -3 dBmV 38 dB 847 800
13 Locked QAM256 477000000 Hz -3 dBmV 38 dB 705 795
14 Locked QAM256 483000000 Hz -3 dBmV 38 dB 749 790
15 Locked QAM256 489000000 Hz -3 dBmV 38 dB 802 684
16 Locked QAM256 495000000 Hz -3 dBmV 38 dB 553 698
17 Locked QAM256 501000000 Hz -4 dBmV 38 dB 639 699
18 Locked QAM256 507000000 Hz -4 dBmV 38 dB 676 752
19 Locked QAM256 513000000 Hz -4 dBmV 38 dB 718 645
20 Locked QAM256 519000000 Hz -4 dBmV 38 dB 587 651
21 Locked QAM256 525000000 Hz -4 dBmV 38 dB 651 720
22 Locked QAM256 531000000 Hz -4 dBmV 38 dB 639 617
23 Locked QAM256 543000000 Hz -5 dBmV 38 dB 744 670
24 Locked QAM256 555000000 Hz -5 dBmV 37 dB 499 644
25 Locked QAM256 561000000 Hz -5 dBmV 37 dB 633 737
26 Locked QAM256 567000000 Hz -4 dBmV 37 dB 667 563
27 Locked QAM256 573000000 Hz -4 dBmV 37 dB 735 453
29 Locked QAM256 585000000 Hz -5 dBmV 37 dB 679 502
30 Locked QAM256 591000000 Hz -5 dBmV 37 dB 609 460
31 Locked QAM256 597000000 Hz -5 dBmV 37 dB 542 530
32 Locked QAM256 603000000 Hz -6 dBmV 37 dB 617 551
33 Locked QAM256 609000000 Hz -5 dBmV 37 dB 862 418
34 Locked QAM256 615000000 Hz -6 dBmV 37 dB 647 475
48 Locked OFDM PLC 722000000 Hz -4 dBmV 37 dB 57160661 1784



Upstream Bonded Channels
Channel ID Lock Status US Channel Type Frequency Width Power
1 Locked SC-QAM 17300000 Hz 6400000 44.0 dBmV
2 Locked SC-QAM 23700000 Hz 6400000 46.3 dBmV
3 Locked SC-QAM 30100000 Hz 6400000 45.8 dBmV
4 Locked SC-QAM 36500000 Hz 6400000 45.0 dBmV
5 Locked SC-QAM 41200000 Hz 1600000 44.3 dBmV



Current System Time:Wed Aug 4 13:54:14 2021

I hope someone here can help because I feel like I've hit a brick wall after that phone call.

Responses

Accepted Solution

Official Employee

 • 

145 Messages

1 m ago

Hey, @user_3ca09d. I wanted to thank you for allowing us to assist you. I'm glad we were able to get the issue resolved and your service is now up to par. If anything comes up, please don't hesitate to reach out, our amazing team is available 24/7! I hope you enjoy the rest of your week and stay safe out there. 

Official Employee

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229 Messages

1 m ago

Hello @user_3ca09d, thank you so much for reaching out to our amazing community here for support with your internet service. We know that having a reliable internet connection is more important than ever these days, and we do appreciate all of the time and effort you have put into troubleshooting this. Our team here is part of our direct corporate office, so we'll ensure that we get to the bottom of this for you. You mentioned that technician came out to your home and reported everything was good. How long ago was that? Also, when you contacted the manufacture of your router, what did they say?

Visitor

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4 Messages

@XfinityKatie The technician came out 19 days ago. The Ubiquiti support said it wasn't the router causing the issue. The router works fine during the outages whereas the cable modem network interface goes down and once it returns the logs are filled with the aforementioned upstream T3 timeouts and messages about resetting the network interface.

I described the problem to a neighbor group to see if anyone else is having issues and someone (I believe he may be a Comcast technician because he was very knowledgeable) said:

I would assume it's the lines. It means that upstream is being overloaded with other people's internet. Those lines are a bit older, and some of the peds have been smashed. There's a rod in each catv ped that grounds it. If the peds have been destroyed the ground rods don't work, and can cause internet errors like the ones your having.

I checked the grounding at the comcast box outside. The grounding wire outside the box is well connected (not sure what is going on inside it though but I assume the technician did this already).

Official Employee

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365 Messages

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Visitor

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4 Messages

Visitor

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4 Messages

1 m ago

For anyone showing up here from Google, the problem ended up being the old coaxial cable coming into the house. Technicians replaced pretty much everything both outside and inside the house in an effort to identify the source of the problem over a series of visits. They confirmed the problem was isolated to my house by checking the logs of my neighbors and confirming my modem was the only one having issues. The only thing left to do was replace the internal, difficult to access cable running from the box outside to my cable modem. We figured out an easier way to route a new cable into the house and they ran that. After they completed running the cable and we got everything hooked up the problem went away. The technicians all did great work with a difficult to diagnose problem.

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