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Constant T3 time-outs and Cable Modem Reboots

Regular Visitor

Constant T3 time-outs and Cable Modem Reboots

Hi Folks,

 

I'm at my wit's end and really hoping someone can help.  For the last couple years Xfinity internet service has been pretty rock solid.  This weekend I started running into lots of issues with very frequent (multiple times an hour) internet dropouts that require me to reboot my modem.  Once the modem comes back up the speeds are amazing and as they usually are....that is...until the next disconnect.

speed.png

 

Due to previous issues I've already replaced about 70% of the coax in my house, minimized all splits from where the coax comes out of the ground to where it goes to the cable modem.  I've got 1 multi-splitter between the source line and my cable modem.

 

I've got an Arris SB8200.  After 2 days of constant reboots, I contacted online customer support.  They reprovisioned my modem and had me manually reset it.  It seemed to work for a while but alas, it's been disconnecting a lot again.

 

This is the error that keeps cropping up my modem's event log:

 

"No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=00:01:5c:9b:12:61;CM-QOS=1.1;CM-VER=3.1;"

 

As you can see from the cable modem status below, Channel 48 seems to have a pretty low SNR and it seems to fluctuate between 27-31 db.

 

Could some of the super smart folks to help me out here with what may be going on?  Is it possible that there's an issue upstream from my house causing these problems?

 

Thanks everyone for the help.  Cheers!

 

(@ComcastKenF  @ComcastZach)

 

modem1.png

 

modem2.png

 

 

 

Expert

Re: Constant T3 time-outs and Cable Modem Reboots

Can't see your pics. Since you are a new poster, they likely need to be approved by a Forum Admin. Or you may need to make a minimum number of posts.

You could try hosting them at one of those free third-party pic hosting sites and post the link to them here.



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Official Employee

Re: Constant T3 time-outs and Cable Modem Reboots

Hello, Kopland. Thanks for reaching out to us for help with this issue. I would like to take a closer look and help restore a reliable service connection for you. Please send me a private message with your first and last name so I can assist. 

 

To send a private message, click my name "ComcastTambrey", then click "send a message".


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Expert

Re: Constant T3 time-outs and Cable Modem Reboots

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. And the downstream power is on the weak side. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.




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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: Constant T3 time-outs and Cable Modem Reboots

Kopland, as I have not heard back from you in some time, I have closed this thread to further comments. I hope you were able to get this issue figured out with your services, but if you still need assistance, please feel free to start a new thread.


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Was your question answered? Mark the post as Best Answer!