Community Forum

Internet keeps randomly dropping

Highlighted
Frequent Visitor

Internet keeps randomly dropping

starting this year my internet starts randomly dropping for no reasons. had contact agent for a few times, had a tech guy come to my home for 2 times. nope its not fixed.. my obeservation is looks like a upstream issue.
1. it happened almost every day at the same time. 2pm. at least for continuesly 2 days. (I could not verify other day bc I'm at work in weekdays)
2. once it drops, it will be back in 20-30 min
3. my xfinity app said my device was offline when issue happens. but all my modem lights were fine and my modem page 192.168.1.1 said it it connected. to prove that at this stage although the app said my device was diconnected, I can still sent the reset signal from my app and can receive it.
4. issue also happended sometimes at late night.
Highlighted
Expert

Re: Internet keeps randomly dropping

Start here;


https://forums.xfinity.com/t5/Your-Home-Network/Connection-Troubleshooting-Tips/m-p/1253575#M94474

 

Post the requested info from here;


https://forums.xfinity.com/t5/Your-Home-Network/Information-Requested-for-Connection-Related-Posts/m...

 



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!
Highlighted
Frequent Visitor

Re: Internet keeps randomly dropping

I just find out that it get drop around 230pm and 230am like a clock..
Highlighted
Expert

Re: Internet keeps randomly dropping

That sounds like a DHCP IP address lease length issue either with them or your router. You haven't posted any of the requested info...



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!
Highlighted
Frequent Visitor

Re: Internet keeps randomly dropping

Hello there,

I have gather these informations:

  • Post your modem’s error logs. 
  • Post the make and model of your modem/gateway.
  • Post the make and model of your router if you have one.
  • Let us know if you contacted Comcast or had a tech visit.
  • Let us know what the lights on your modem are doing when you are having problems.

 

1. 

Model: CM-32_AC2600
Firmware Version: 1.0.1.5
PIN Code: 54335561
Gateway Serial Number: JBIABT001341
CM MAC Address: 2C:FD:A1:90:BE:18
Acquire Downstream Channel : 579000 KHz
Connectivity State : OPERATIONAL
Last Operational Time : Sun Oct 13 14:25:12 UTC 2019

2019-10-13 13:53:31 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-13 13:53:31 [CRITICAL] Ranging Request Retries exhausted
2019-10-13 13:53:31 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-13 13:53:31 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 13:57:20 [CRITICAL] Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
2019-10-13 13:58:00 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 13:58:40 [WARNING] MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
2019-10-13 14:18:30 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 14:19:14 [CRITICAL] Ranging Request Retries exhausted
2019-10-13 14:19:14 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-13 14:19:15 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 14:19:50 [CRITICAL] Ranging Request Retries exhausted
2019-10-13 14:19:50 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-13 14:19:51 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 14:20:18 [CRITICAL] Ranging Request Retries exhausted
2019-10-13 14:20:18 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-13 14:20:19 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 14:24:02 [CRITICAL] Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
2019-10-13 14:24:47 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-13 14:25:08 [WARNING] MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1

]

signal1signal1

signal2signal2

2. My modem is ASUS cm-32_ac2600

3. Tech visited twice, first time said I had a TV spliter so he get rid of it,  next time found another TV spliter. but the issue still presisit

4. When issue happens, everything looks fine, 4 lights were on and my modem status said it's connceted. although I got a modem disconnect status in my xfinity app, I can still send reset signal back to my modem and my modem can receive it just fine. in about 15min-30min, internet get restored, and from my past 3 day experience, the drop happened around 2pm pst and 2am pst. like it  was beening scheduled 

Highlighted
Frequent Visitor

Re: Internet keeps randomly dropping

for some reason the screenshot didn't work, so I will just post the singal here:

USfreqInfo:
['1', '3', 'Locked', '30300000', '64 QAM', '5120000', 'ATDMA', '38.00 dBmV']
['2', '4', 'Locked', '36700000', '64 QAM', '5120000', 'ATDMA', '36.75 dBmV']
['3', '2', 'Locked', '23700000', '64 QAM', '5120000', 'ATDMA', '38.75 dBmV']
['4', '1', 'Locked', '17300000', '64 QAM', '5120000', 'ATDMA', '39.50 dBmV']
['0', '---', 'Unlocked', '0', '---', '---' , '---', '---']
['0', '---', 'Unlocked', '0', '---', '---' , '---', '---']
['0', '---', 'Unlocked', '0', '---', '---' , '---', '---']
['0', '---', 'Unlocked', '0', '---', '---' , '---', '---']

DSfreqInfo:
['1', '1(Prm)', 'Locked', '579000000', '256 QAM', '5360000', '37.636 dB', '3.80 dBmV']
['2', '2', 'Locked', '477000000', '256 QAM', '5360000', '37.636 dB', '4.80 dBmV']
['3', '3', 'Locked', '483000000', '256 QAM', '5360000', '37.356 dB', '4.90 dBmV']
['4', '4', 'Locked', '489000000', '256 QAM', '5360000', '37.356 dB', '5.00 dBmV']
['5', '5', 'Locked', '495000000', '256 QAM', '5360000', '37.636 dB', '5.00 dBmV']
['6', '6', 'Locked', '507000000', '256 QAM', '5360000', '37.356 dB', '5.00 dBmV']
['7', '7', 'Locked', '513000000', '256 QAM', '5360000', '37.636 dB', '5.00 dBmV']
['8', '8', 'Locked', '519000000', '256 QAM', '5360000', '37.356 dB', '4.50 dBmV']
['9', '9', 'Locked', '525000000', '256 QAM', '5360000', '37.636 dB', '4.70 dBmV']
['10', '10', 'Locked', '531000000', '256 QAM', '5360000', '37.636 dB', '4.60 dBmV']
['11', '11', 'Locked', '537000000', '256 QAM', '5360000', '37.356 dB', '4.20 dBmV']
['12', '12', 'Locked', '543000000', '256 QAM', '5360000', '37.636 dB', '4.40 dBmV']
['13', '13', 'Locked', '549000000', '256 QAM', '5360000', '37.356 dB', '4.40 dBmV']
['14', '14', 'Locked', '555000000', '256 QAM', '5360000', '37.356 dB', '4.30 dBmV']
['15', '15', 'Locked', '561000000', '256 QAM', '5360000', '37.636 dB', '4.10 dBmV']
['16', '16', 'Locked', '567000000', '256 QAM', '5360000', '37.636 dB', '4.30 dBmV']
['17', '17', 'Locked', '573000000', '256 QAM', '5360000', '37.356 dB', '3.90 dBmV']
['18', '18', 'Locked', '585000000', '256 QAM', '5360000', '37.356 dB', '4.00 dBmV']
['19', '19', 'Locked', '591000000', '256 QAM', '5360000', '37.636 dB', '4.20 dBmV']
['20', '20', 'Locked', '597000000', '256 QAM', '5360000', '37.636 dB', '4.20 dBmV']
['21', '21', 'Locked', '603000000', '256 QAM', '5360000', '37.356 dB', '4.40 dBmV']
['22', '22', 'Locked', '609000000', '256 QAM', '5360000', '37.636 dB', '4.50 dBmV']
['23', '23', 'Locked', '615000000', '256 QAM', '5360000', '37.356 dB', '4.30 dBmV']
['24', '24', 'Locked', '621000000', '256 QAM', '5360000', '37.356 dB', '4.60 dBmV']
['25', '25', 'Locked', '627000000', '256 QAM', '5360000', '37.300 dB', '4.80 dBmV']
['26', '26', 'Locked', '633000000', '256 QAM', '5360000', '37.300 dB', '4.30 dBmV']
['27', '27', 'Locked', '639000000', '256 QAM', '5360000', '36.900 dB', '4.60 dBmV']
['28', '28', 'Locked', '645000000', '256 QAM', '5360000', '37.900 dB', '4.90 dBmV']
['29', '29', 'Locked', '651000000', '256 QAM', '5360000', '37.300 dB', '4.70 dBmV']
['30', '30', 'Locked', '681000000', '256 QAM', '5360000', '37.300 dB', '5.70 dBmV']
['31', '31', 'Locked', '687000000', '256 QAM', '5360000', '37.600 dB', '6.30 dBmV']
['32', '32', 'Locked', '693000000', '256 QAM', '5360000', '37.300 dB', '6.10 dBmV']

Highlighted
Frequent Visitor

Re: Internet keeps randomly dropping

got the log when it drops today:

Model: CM-32_AC2600
Firmware Version: 1.0.1.5
PIN Code: 54335561
Gateway Serial Number: JBIABT001341
CM MAC Address: 2C:FD:A1:90:BE:18
Acquire Downstream Channel : 579000 KHz
Connectivity State : OPERATIONAL
Last Operational Time : Tue Oct 15 06:52:41 UTC 2019

2019-10-15 01:54:41 [WARNING] MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
2019-10-15 12:19:29 [MAJOR] DCC rejected authentication failure
2019-10-15 12:19:30 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 12:21:09 [CRITICAL] Ranging Request Retries exhausted
2019-10-15 12:21:09 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-15 12:21:24 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 13:51:18 [CRITICAL] Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
2019-10-15 13:52:00 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 06:52:37 [WARNING] MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
2019-10-15 12:19:01 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 12:24:01 [CRITICAL] Ranging Request Retries exhausted
2019-10-15 12:24:01 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-15 12:24:06 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 12:24:23 [CRITICAL] Ranging Request Retries exhausted
2019-10-15 12:24:23 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-15 12:24:23 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 19:10:39 [CRITICAL] Ranging Request Retries exhausted
2019-10-15 19:10:39 [CRITICAL] Unicast Maintenance Ranging attempted - No response - Retries exhausted
2019-10-15 19:10:40 [CRITICAL] No Ranging Response received - T3 time-out
2019-10-15 19:14:32 [CRITICAL] Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out


USfreqInfo:
['1', '3', 'Locked', '30300000', '64 QAM', '5120000', 'ATDMA', '-1.00 dBmV']
['2', '4', 'Locked', '36700000', '64 QAM', '5120000', 'ATDMA', '-1.00 dBmV']
['3', '2', 'Locked', '23700000', '64 QAM', '5120000', 'ATDMA', '-1.00 dBmV']
['4', '1', 'Locked', '17300000', '64 QAM', '5120000', 'ATDMA', '-1.00 dBmV']

 

downstream was empty

Highlighted
Expert

Re: Internet keeps randomly dropping

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!
Highlighted
Official Employee

Re: Internet keeps randomly dropping

Greetings, domodog! We appreciate you taking the time to reach out to us here on the forums. We hope you are having an amazing day. We apologize to hear of the issues you are running into with the internet. Certainly frustrating having the internet drop out like that. As EG has mentioned we would need to take a deeper look into the signal. Can you please send us a PM with your first and last name so we may further assist you?

 

To send a private message, please click the name "Comcast_Support" then select "Send a Message" on the right side.


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!
Highlighted
Frequent Visitor

Re: Internet keeps randomly dropping

just sent a message:)
Highlighted
New Poster

Re: Internet keeps randomly dropping

I'm having the same problem - exactly!  It started a couple of weeks ago after years of no problems with the same home network setup.  Internet drops off, WiFi still A-OK and all llights on on the modem.

I thought it might be an eqipment issue, so bought a new modem/router (Arris), still the same problem.  Intenet drops off for 15-20 minutes and then comes back on.  Two different modems and different routers, same problem.  

BTW, no luck getting in touch with a Comcast tech.  Ran all of the available checks from the App and website - no joy!

 

Highlighted
New Poster

Re: Internet keeps randomly dropping

This is happening for me as well! Have you received a response yet?