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Gigabit installed today - slow with millions of errors on the modem

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Frequent Visitor

Gigabit installed today - slow with millions of errors on the modem

Hi - my gigabit was installed today (Chicago suburbs) using a brandnew Motorol MB8600 connected to an edgerouter X gigabit router.  The computer i am using is hardwired (gigabit) into the router and is the only device attached to Xfinity.   

 

My upload speeds are well short of 940mb (download is fine), with the best i've seen via Speedtest.net being 320mbps down.   I have no idea if this is normal or not, but cable modem is showing TONS of errors:  

   Downstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusModulationChannel IDFreq. (MHz)Pwr (dBmV)SNR (dB)CorrectedUncorrected
   1LockedQAM25638471.01.440.21632362008
   2LockedQAM2561495.02.040.31046638165
   3LockedQAM2562507.02.439.71248342127
   4LockedQAM2563513.02.139.81163435893
   5LockedQAM2564519.02.237.41337845633
   6LockedQAM2565525.02.436.71625058422
   7LockedQAM2566531.02.338.31649961269
   8LockedQAM2567537.02.936.51517451663
   9LockedQAM2568543.02.740.21245139698
   10LockedQAM2569549.02.840.61213538483
   11LockedQAM25610555.03.040.81480351375
   12LockedQAM25611561.03.040.61598561355
   13LockedQAM25612567.03.641.01508655860
   14LockedQAM25613573.03.640.91315744458
   15LockedQAM25614579.03.640.71151436261
   16LockedQAM25615585.03.840.11266642699
   17LockedQAM25616591.04.039.41527153842
   18LockedQAM25617597.04.438.31559356475
   19LockedQAM25618603.04.538.31376347430
   20LockedQAM25619609.04.438.71176838667
   21LockedQAM25620615.04.540.21178336133
   22LockedQAM25621621.04.640.7334008103503
   23LockedQAM25622627.04.638.427764902055068
   24LockedQAM25623633.04.840.656888608971410
   25LockedQAM25624639.04.835.03902994357986744
   26LockedQAM25625645.05.033.02819138855919728
   27LockedQAM25626651.05.241.21227737893
   28LockedQAM25627657.05.141.61265942142
   29LockedOFDM PLC37762.06.336.5550712642800
   30LockedQAM25639477.02.040.41364145527
   31LockedQAM25640483.01.640.61420149065
   32LockedQAM25641489.01.740.51627061739

This is after four hours connected, with little actual usage.   

 

Error log snippet on the modem:

Time  Priority  Description 
   18:33:47
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 23 24 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:01
Mon Jul 20 2020
 Warning (5) MDD message timeout;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:11
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 23 24 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:15
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 22 23 24 25 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:37
Mon Jul 20 2020
 Warning (5) MDD message timeout;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:38
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 2; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:40
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 23 24; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:43
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 23 24 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:34:51
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 22 23 24 25 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:19
Mon Jul 20 2020
 Warning (5) MDD message timeout;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:20
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 24 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:23
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 2; Chan ID: 23; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:25
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 23 24 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:32
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 22 23 24 25 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:39
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:35:47
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:36:20
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 22 23 24 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:36:39
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:36:46
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 20; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:37:10
Mon Jul 20 2020
 Warning (5) MDD message timeout;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;
   18:37:11
Mon Jul 20 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 22 23 24 25 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:40:36:61:bc:7d;CMTS-MAC=00:01:5c:69:f4:4f;CM-QOS=1.1;CM-VER=3.1;

 

 There is little cabling in place for this run, and it is dedicated to just the cable modem.  The cable comes from the pole, is connected to a ~75ft line to my office, whihc is terminated at an inside jack.   A 10ft cable connects from the jack to the modem.    The 75ft line may have been run by a directv installer a long while back, but it is now solely connected to the modem outlet (i confirmed this visually).  The 10ft cable may be a cheap, home depot quality cable.   

 

Any suggestions or tips?  Could bad cabling drive that level of errors? 

 

Thanks!

 

 

 

Highlighted
Expert

Re: Gigabit installed today - slow with millions of errors on the modem

Please also post the upstream power level numbers.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Frequent Visitor

Re: Gigabit installed today - slow with millions of errors on the modem

   Upstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusChannel TypeChannel IDSymb. Rate (Ksym/sec)Freq. (MHz)Pwr (dBmV)
   1LockedSC-QAM5512035.646.3
   2LockedSC-QAM6512029.246.8
   3LockedSC-QAM7512022.846.5
   4LockedSC-QAM8512016.446.5
   5LockedSC-QAM10128039.644.0

THank you! 

Highlighted
Expert

Re: Gigabit installed today - slow with millions of errors on the modem

Those are good as well. 

Even though the signal stats looked o/k at that snapshot in time, the error log entries and the bit errors  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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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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Frequent Visitor

Re: Gigabit installed today - slow with millions of errors on the modem

Thank you EG! 

Highlighted
Official Employee

Re: Gigabit installed today - slow with millions of errors on the modem

Hello @Fingolfin, thanks for reaching out to our Digital Care Team through our Forums page. We appreciate you being a customer and getting our Gigabit speeds installed. We definitely want you to be receiving the speeds you're paying for. I would love to further troubleshoot and assist you with this speed concern. 

 

Can you please send me a Private Message including your first and last name as it appears on the account? 

 

To send me a Private Message, please click my name “ComcastAmira” and click “Send a message". 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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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Frequent Visitor

Re: Gigabit installed today - slow with millions of errors on the modem

Pm sent.  Ty!

Highlighted
Frequent Visitor

Re: Gigabit installed today - slow with millions of errors on the modem

@ComcastAmira 

 

I sent a PM on the 21st but have not had any reply.  

 

This morning my Gibabit internet is speedtesting at 94mb down, 10% of what I am paying for.   SInce installation it has never exceeded 400mb down in any testing.   

 

Interesting, shortened the connection and removed a cable and am now largely error free on the modem, but the speed is still woefully inadequate.   I tried Comcast internet once 8 years ago when we moved in, but cancelled within a month b/c it was unreliable and not performing.   Tempting to consider that again, after 5 days.  My uverse, while a fraction of this theoretical connection, is solid as a rock and performs to spec.  

 

   Downstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusModulationChannel IDFreq. (MHz)Pwr (dBmV)SNR (dB)CorrectedUncorrected
   1LockedQAM25638471.03.040.500
   2LockedQAM2561495.03.640.700
   3LockedQAM2562507.04.040.600
   4LockedQAM2563513.03.840.700
   5LockedQAM2564519.04.040.900
   6LockedQAM2565525.04.240.800
   7LockedQAM2566531.03.940.800
   8LockedQAM2567537.04.441.000
   9LockedQAM2568543.04.241.000
   10LockedQAM2569549.04.441.100
   11LockedQAM25610555.04.741.300
   12LockedQAM25611561.04.841.400
   13LockedQAM25612567.05.241.300
   14LockedQAM25613573.05.141.200
   15LockedQAM25614579.05.241.200
   16LockedQAM25615585.05.541.500
   17LockedQAM25616591.05.741.500
   18LockedQAM25617597.06.041.500
   19LockedQAM25618603.06.141.600
   20LockedQAM25619609.06.041.500
   21LockedQAM25620615.06.141.700
   22LockedQAM25621621.06.241.700
   23LockedQAM25622627.06.241.500
   24LockedQAM25623633.06.341.500
   25LockedQAM25624639.06.241.600
   26LockedQAM25625645.06.441.600
   27LockedQAM25626651.06.741.800
   28LockedQAM25627657.06.541.800
   29LockedOFDM PLC37762.07.440.0330482350
   30LockedQAM25639477.03.640.600
   31LockedQAM25640483.03.340.500
   32LockedQAM25641489.03.440.700



   Upstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusChannel TypeChannel IDSymb. Rate (Ksym/sec)Freq. (MHz)Pwr (dBmV)
   1LockedSC-QAM5512035.646.3
   2LockedSC-QAM6512029.246.8
   3LockedSC-QAM7512022.846.3
   4LockedSC-QAM8512016.446.5
   5LockedSC-QAM10128039.644.0

 

Highlighted
Official Employee

Re: Gigabit installed today - slow with millions of errors on the modem

@Fingolfin, thanks for sending me a private message. I apologize for the delay as we are still pretty backed up due to COVID-19. We definitely want to find the underlying cause of this speed issue. I have responded to your private message and look forward to hearing back from you. 


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Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. 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!