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Intermittent packet loss

Frequent Visitor

Intermittent packet loss

My connection has been pretty rock solid for the last couple years, but recently (last couple months) I've started to see some fairly big packet loss spikes. At one point, there was an outage lasting a few hours and then everything was better again for awhile. A saw a number of trucks in the area over the next couple weeks, and my connection is back to having packet loss again. Looking at the modem diagnostics, I have a ton of uncorrrectables on the downstream (this is after resetting the modem, so these are just from past couple weeks) and the power levels are looking pretty high compared to where they used to be (used to be close to 0, and I have an attenuator on the line already). Upstream is still hanging in there, but the power levels have creeped higher there also.

 

Any help would be appreciated. Thanks!

 

downstream.png
upstream.png
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Expert

Re: Intermittent packet loss

The up or down power levels are not that high. Please post the RF error log events as well.



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Frequent Visitor

Re: Intermittent packet loss

Thanks EG, here's the log:

 

Tue Aug 13 23:06:55 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Tue Aug 13 23:06:55 2019
3
SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Tue Aug 13 23:06:55 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Tue Aug 13 23:06:59 2019
5
Lost MDD Timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Thu Jan 01 00:09:15 1970
3
No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Aug 14 03:43:40 2019
6
TLV-11 - unrecognized OID;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Aug 14 03:48:05 2019
3
No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Aug 14 14:55:46 2019
3
Ranging Request Retries exhausted;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Aug 14 14:55:46 2019
3
Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Aug 14 14:56:10 2019
3
No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:15 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:15 2019
3
SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:16 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:16 2019
3
SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:16 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:20 2019
5
Lost MDD Timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 15:30:22 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 23 19:08:20 2019
3
No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Tue Aug 27 23:52:56 2019
5
RCS Partial Service;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Wed Aug 28 03:52:50 2019
3
No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;

Expert

Re: Intermittent packet loss

Is this with a WiFi connection ? If so, for a test, does a computer hardwired directly to the router / gateway device with an ethernet cable have the same problem ?



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Frequent Visitor

Re: Intermittent packet loss

This is a hardwired ethernet connection. The packetloss I'm seeing is reported as upstream loss, not downstream. It will spike all the way to about 25-50% upstream loss for a couple seconds then go back to normal. This may happen every few minutes.

 

Up until a couple months ago, I would never see this happen. But now it has become fairly normal. With the comcast trucks I saw on my street around the time this started happening, I'm wondering if some new customers have come online that could be related to this. Let me know if I can provide anything else to help you troubleshoot - I can capture some ping logs, etc.

Expert

Re: Intermittent packet loss

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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Frequent Visitor

Re: Intermittent packet loss

Thanks very much for your help EG. I did just capture a ping plot with packetless for my first 3 hops to give you an idea of what is going on.

 

 

68.86.92.89c.png
Frequent Visitor

Re: Intermittent packet loss

Any Comcast employees out there able to help on this one? Should I just call in and have them send out a tech? I think this one may require a line tech.

Expert

Re: Intermittent packet loss

I'm going to re-escalate this for you.



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Official Employee

Re: Intermittent packet loss

Hi Tasc22, thank you for reaching out here and welcome to our coummity forums.  I understand you are having issues with your internet service and would like to help review further for you.  Please send us a private message with your full name to begin.

 

Thank you 


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