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Intermittent Internet Issues

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Intermittent Internet Issues

Hi,

 

I have had this issue for 8 or so weeks now.

 

Basically the internet goes down for about 10 minutes from about once a day to once every few hours. It then comes back on its own without me doing anything. 

 

I use my own router and my owm modem. 

TP-Link TC7650 DOCSIS 3.0 (24x8) High Speed Cable Modem 

TP-Link AC1750 Smart WiFi Router

 

This issue shows up in the modem logs. 

 

Time Priority Description

Sat Oct 10 13:08:12 2020Notice (6)Honoring MDD; IP provisioning mode = IPv6
Sat Oct 10 13:08:06 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 13:07:56 2020Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c4...
Sat Oct 10 13:03:36 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 13:02:37 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 13:02:37 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 13:02:37 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 12:08:40 2020Notice (6)Honoring MDD; IP provisioning mode = IPv6
Sat Oct 10 12:08:32 2020Critical (3)No Ranging Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM-QOS=1.0;CM-VER=3.0;
Sat Oct 10 12:08:20 2020Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c4...
Sat Oct 10 12:04:00 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 12:03:51 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 12:03:51 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 12:03:51 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 11:54:31 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 11:54:31 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 11:54:31 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 11:54:30 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 11:54:30 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 11:54:30 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 11:54:29 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 11:54:29 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 11:54:29 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 11:44:40 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 11:44:40 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 11:44:40 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 10:59:40 2020Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;CM...
Sat Oct 10 10:59:40 2020Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;C...
Sat Oct 10 10:59:40 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c4:71:54:18:38:02;CMTS-MAC=00:01:5c:6d:1c:51;...
Sat Oct 10 10:13:38 2020Notice (6)Honoring MDD; IP provisioning mode = IPv6
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Expert

Re: Intermittent Internet Issues

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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Re: Intermittent Internet Issues

Procedure Status Comment
Acquire Downstream Channel627000000 HzLocked
Connectivity StateOKOperational
Boot StateOKOperational
Configuration FileOKd11_m_tc7650_silver_c01.cm
SecurityEnabledBPI+

 
Downstream Bonded Channels

Channel Status Modulation Channel ID Frequency Power SNR
1LockedQAM25629627000000 Hz2.8 dBmV37.1 dB
2LockedQAM25613531000000 Hz2.2 dBmV37.2 dB
3LockedQAM25614537000000 Hz2.5 dBmV37.2 dB
4LockedQAM25615543000000 Hz2.5 dBmV37.2 dB
5LockedQAM25616549000000 Hz2.6 dBmV37.2 dB
6LockedQAM25617555000000 Hz3.0 dBmV37.3 dB
7LockedQAM25618561000000 Hz3.0 dBmV36.4 dB
8LockedQAM25619567000000 Hz3.1 dBmV37.4 dB
9LockedQAM25620573000000 Hz3.0 dBmV37.4 dB
10LockedQAM25621579000000 Hz2.9 dBmV37.3 dB
11LockedQAM25622585000000 Hz2.9 dBmV37.2 dB
12LockedQAM25623591000000 Hz2.6 dBmV37.1 dB
13LockedQAM25624597000000 Hz2.5 dBmV37.0 dB
14LockedQAM25625603000000 Hz2.4 dBmV37.1 dB
15LockedQAM25626609000000 Hz2.7 dBmV37.2 dB
16LockedQAM25627615000000 Hz2.6 dBmV37.2 dB
17LockedQAM25628621000000 Hz3.0 dBmV37.2 dB
18LockedQAM25630633000000 Hz3.2 dBmV37.2 dB
19LockedQAM25631639000000 Hz3.0 dBmV36.8 dB
20LockedQAM25632645000000 Hz3.0 dBmV37.1 dB
21LockedQAM25633651000000 Hz2.9 dBmV37.1 dB
22LockedQAM25634657000000 Hz2.9 dBmV37.1 dB
23LockedQAM25635663000000 Hz2.9 dBmV37.2 dB
24LockedQAM25636669000000 Hz2.6 dBmV36.8 dB
Upstream Bonded Channels

 

Channel Status Channel Type Channel ID Symbol Rate Frequency Power

1LockedATDMA92560 ksym/sec40400000 Hz42.6 dBmV
2LockedATDMA15120 ksym/sec35600000 Hz43.0 dBmV
3LockedATDMA25120 ksym/sec29200000 Hz42.8 dBmV
4LockedATDMA35120 ksym/sec22800000 Hz43.5 dBmV
5LockedATDMA45120 ksym/sec16400000 Hz43.8 dBmV
6Not LockedUnknown00 ksym/sec0 Hz0.0 dBmV
7Not LockedUnknown00 ksym/sec0 Hz0.0 dBmV
8Not LockedUnknown00 ksym/sec0 Hz0.0 dBmV
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Expert

Re: Intermittent Internet Issues

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 !



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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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Official Employee

Re: Intermittent Internet Issues

Hi @awst! Thanks for using the Xfinity Forum. I'd be more than happy to take a deeper look at your intermittent issues and help find a resolution. Please send me a private message with your full name as it's listed on your billing statement. To send a private message, click on my name ComcastChe, then click Send a message. 


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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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