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MB8600 - Frequent packet loss and disconnects after 12 months of no issues

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MB8600 - Frequent packet loss and disconnects after 12 months of no issues

Hello. My Xfinity connection has unexpectedly deteriorated after nearly a year of no-drama operation. No changes in hardware, wiring or anything else. Of course the self-diagnose tool on this website and cust service reps say thinks look "OK." They are not. 

 

First, here is my router's (pfSense) quality/uptime graph. Spikes are packet loss/drops. You can see they started on 10/27 and haven't stopped since.

 

1 month view: https://imgur.com/cIfgJSc

 

1 week view: https://imgur.com/q10CDRh

 

This is measured at the router level which is bridged directly off a Motorola MB8600. In the MB8600 I am seeign the following "Event Log" entries (these messages go on ad infinitum):

 

	13:08:09
Thu Oct 31 2019	 	Notice (6)	 	CM-STATUS message sent. Event Type Code: 5; Chan ID: 13 14 15 17 18 19 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:09
Thu Oct 31 2019	 	Critical (3)	 	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:14
Thu Oct 31 2019	 	Notice (6)	 	CM-STATUS message sent. Event Type Code: 4; Chan ID: 1 2 3 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=
   	13:08:26
Thu Oct 31 2019	 	Warning (5)	 	MDD message timeout;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:27
Thu Oct 31 2019	 	Notice (6)	 	CM-STATUS message sent. Event Type Code: 5; Chan ID: 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:32
Thu Oct 31 2019	 	Warning (5)	 	MDD message timeout;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:35
Thu Oct 31 2019	 	Notice (6)	 	CM-STATUS message sent. Event Type Code: 4; Chan ID: 1 2 3 4 6 7 8 9 10 11 12 13 14 15 16 18 19 20 23 24 27 30 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:35
Thu Oct 31 2019	 	Notice (6)	 	CM-STATUS message sent. Event Type Code: 1; Chan ID: 17 21 22 25 26 28 29 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
   	13:08:35
Thu Oct 31 2019	 	Notice (6)	 	CM-STATUS message sent. Event Type Code: 5; Chan ID: 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:XX:XX:XX;CMTS-MAC=00:38:df:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

Here are the connection statistics for the modem: 

https://imgur.com/gWnoPxs

https://imgur.com/wdM2HSO

 

I have rebooted the modem (and rest of the system) as has Xfinity remotely. 

 

Any ideas? In advance, thank you. 

 

 

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Expert

Re: MB8600 - Frequent packet loss and disconnects after 12 months of no issues

Can't see your pics. Since you are a new poster, they need to be approved by a Forum Admin. That could take some time. In the interim, you could try hosting them at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to them here.



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Re: MB8600 - Frequent packet loss and disconnects after 12 months of no issues

Thanks! Was frustrated at why they weren't showing up. Edited original post to Link to Imgur copies for now.

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Expert

Re: MB8600 - Frequent packet loss and disconnects after 12 months of no issues

Some of the SNR's are on the low side and the may be intermittently fluctuating even lower out of spec. Seems that there may be some noise ingress leaking into the line(s) somehere. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity, 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.
Was your question answered? Mark the post as Best Answer!
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New Poster

Re: MB8600 - Frequent packet loss and disconnects after 12 months of no issues

Update: Comcast called and said they discovered a problem affecting the neighborhood and have corrected it. We'll see if the connection stablizes. 

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Expert

Re: MB8600 - Frequent packet loss and disconnects after 12 months of no issues

One can hope.... 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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Regular Contributor

Re: MB8600 - Frequent packet loss and disconnects after 12 months of no issues


@ILLCOMM wrote:

Update: Comcast called and said they discovered a problem affecting the neighborhood and have corrected it. We'll see if the connection stablizes. 


Can we get an update?