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Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T3 TO

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Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T3 TO

Daily I am having connection drops.  I have a Motoroloa MB 7420 Modem, connected to a Netgear Nighthawk R6700.  The issues started in the spring, or that is when i noticed them.  Many troubleshooting sessions and 2 visits by Comcast techs resulted in 1) a new cable installed between my house and the road, and 2) ditching the Comcast modem and installing my own.  For several months, the problems seems to subside...then about a month ago, I started having them again.  I have had 3 calls with support with no solution.  I was told that they are not dispatching techs due to COVID UNLESS your connection is completely down.  Below is an excerpt from the logs.  Each time there is an issue, this sequence of log entries is repeated.  Any assistance will be much appreciated.

 

Nathan

 

Sun Aug 23 14:26:11 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.1;CM-VER=3.0;
Sun Aug 23 14:28:21 2020 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.1;CM-VER=3.0;
Sun Aug 23 14:28:45 2020 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.0;CM-VER=3.0;
Sun Aug 23 14:29:05 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.0;CM-VER=3.0;
Sun Aug 23 14:29:38 2020 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.0;CM-VER=3.0;
Sun Aug 23 14:29:46 2020 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.0;CM-VER=3.0;
Sun Aug 23 14:29:53 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.0;CM-VER=3.0;
Sun Aug 23 14:29:57 2020 Notice (6) Honoring MDD; IP provisioning mode = IPv6
Sun Aug 23 14:31:00 2020 Warning (5) MDD message timeout;CM-MAC=00:40:36:63:c7:30;CMTS-MAC=58:97:bd:98:71:5b;CM-QOS=1.1;CM-VER=3.0;

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Expert

Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.






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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Downstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusModulationChannel IDFreq. (MHz)Pwr (dBmV)SNR (dB)CorrectedUncorrected
1LockedQAM2561447.01.640.380
2LockedQAM2562453.01.440.3410
3LockedQAM2563459.01.840.4330
4LockedQAM2564465.02.140.5258
5LockedQAM2565471.02.540.880
6LockedQAM2566477.02.640.840
7LockedQAM2567483.02.240.5340
8LockedQAM2568489.02.540.7160
9LockedQAM2569495.02.840.8170
10LockedQAM25610507.03.337.850
11LockedQAM25611513.03.141.1230
12LockedQAM25612519.03.141.1320
13LockedQAM25613525.03.241.160
14LockedQAM25614531.03.241.1240
15LockedQAM25615537.03.241.010
16LockedQAM25616543.03.040.7160
Total      2938

 

 

 Upstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusChannel TypeChannel IDSymb. Rate (Ksym/sec)Freq. (MHz)Pwr (dBmV)
1LockedATDMA2512029.243.8
2LockedATDMA1512035.642.8
3LockedATDMA3512022.842.8
4LockedATDMA4512016.442.3
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Expert

Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

The signal stats are good. Is this with a WiFi connection ? If so, for a test, does a computer / device hardwired directly to the MB 7420 Modem with an ethernet cable have the same problem ?

With this test, we are trying to isolate this from being either a WiFi-/ router only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good step of troubleshooting before we proceed any further.



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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

I have tested that scenario.  I have connected a laptop computer and internet TV with direct wire during the connection drops and there is no connectivity with them.

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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Did you power cycle the modem after connecting each of them ?



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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

No.  Usually, connectivity returns within 1-4 minutes.  Power cycle also re-engages connectivity.  That is great, however, audio/video calls over internet get dropped which causes problems for myself and my child students.

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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Just so you know, you MUST power cycle/reboot the modem each and every time that you change the device that is being directly connected to it in order for that device to be able to get an internet connection. 

 

That said. 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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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Hello noxvillenate, thanks for creating a post. Let's look into your signal levels to see what could be causing your constant disconnects, I have a few tools here that will help me pinpoint the issue so that we can get this taken care of. To continue with troubleshooting could you please send me a private message with your full name by clicking on my name (ComcastAmir) and then click "Send a message"?


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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

I have tried multiple times to reach out to ComcastAmir with no response.  If there are others who may assist, I would be grateful.  

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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

I'm going to re-escalate this.



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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

FYI...out of the blue yesterday, I received a text that Comcast is now scheduling in home tech support visits again.  I have a tech scheduled to come out tomorrow to troubleshoot.  I will update this ticket with the results.  Thanks! Nathan

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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Good luck with it ! Please post back with how things turn out.



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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Hi Nathan. We apologize for our delay in getting back with you. I was able to located and review the diagnostics of your modem and I do see an issue with your T3 Timeouts being high, and your Upstream Receive signal intermittently fluctuating. At this time that pending technician visit is the best thing to get your service performance back to where it needs to be. If you would like to discuss the details of your account, or the pending tech visit, please send me a private message. You can click my name (ComcastJoeTru) to view my profile and send me a private message. Click "Send a private message" and private message me.

 

Thanks for hanging in there with us. 


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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Please escalate as the attempts to repair last Wednesday have not resulted in a solution.  We have had MANY drops with the same errors since the Comcast tech was here

Thank you,

Nathan

 

NOTE:  I have reached out to you @ComcastJoeTru via private message.

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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

@ComcastJoeTru @ComcastAmir @EG 

 

It has almost been a week since I reported the tech visit DID NOT repair my issue.  Also 9/4 was the last I have heard from anyone on this post.  I was told that escalation to a higher department @ Comcast was the next step.  Also the tech who worked at my home mentioned the best way to get the support I need is to go throught this support forum.

 

Will someone please assist with escalation?

Thanks in advance!

Nathan (@knoxvillenate)

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Expert

Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

I'll try to re-escalate this once again.... Good luck !



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Re: Multiple Connection Drops Daily - Started Unicast Maintenance Ranging - No Response received - T

Hello @knoxvillenate, I can't apologize enough for the delays in us getting back to you and the continued connection issues you have been experiencing. We absolutely want to get to the bottom of this and I would love to assist you! I have responded to your private message and look forward to working on this with you! 


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