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Having ongoing T3 / T4 errors causing significant service issues

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Having ongoing T3 / T4 errors causing significant service issues

I have an ongoing issue with my Comcast Internet service that has been present since we had our service installed 3-4 months ago.  I have placed multiple tech support calls and had multiple visits from service techs.  I have had many coax connectors replaced and even the 0db-gain splitter amp replaced, and techs have reviewed signal levels in my house and at my street node.  From what I can tell everything is fine at my house.  I think the issue is upstream in the cable plant but every call to customer service results in "we show everything is fine in our network."  


If you review this screen cap from my router which graphs connectivity testing over time to Google's DNS server you can see that I suffer significant packet lost every day - up to ~50%!  It is intermittent and it does clear up, but then it comes right back the next day.  BTW, the Comcast service is on "WAN 1" in this pic:


Comcast packet loss (redacted).png

Here is my cable modem status and signal levels:


Cable modem status.png 


And here is my cable modem event log showing *many* T3 / T4 errors, and this is just from the one day:


Cable modem log.png


This problem has been so bad that I have had to add another ISP link to my router to be able to work.  I am paying for Comcast Internet service and not able to use it to the point of having to pay for another provider at the same time.  Beyond frustrated...


Help me Obi Wan Kenobi... 



Re: Having ongoing T3 / T4 errors causing significant service issues

Hi @Mr_Mach1,

Since you've already had a tech visit...


I've asked an employee to check the CMTS for real-time and historical RF signal reports from your modem. They can also check your local node/plant for any degradation or error reports. You can expect a reply in this thread. 

"Keepin' it clean since '09"
I am not a Comcast employee, just a moderator.
Official Employee

Re: Having ongoing T3 / T4 errors causing significant service issues

Hi Mr_Mach1, 


Sorry for the experience you've been having with your internet service. I'd like to investigate this further to see if I can help isolate the cause of your issues. In order assist you, please send me a private message verifying your first and last name, and the full account number or phone number associated with your services.


To send a private message click on my name "ComcastChe", then click private message me.