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Signal loss... RNG-RSP CCAP, T3 Timeout, etc

Regular Visitor

Signal loss... RNG-RSP CCAP, T3 Timeout, etc

Started having signal loss issues a few days ago. Recently upgraded to gigabit a month ago but until just recently we didnt have this issue. No hardware changes at all.

 

If someone is going to tell me my signal levels or SNR is off, please also tell me what the accepted range is.

 

Thanks!

 

Netgear CM1000 

Firmware Version 
V5.01.04

 

2019-08-25, 18:31:23 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2019-08-25, 18:31:18 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:31:04 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:31:00 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:30:59 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:30:56 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:30:55 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:30:53 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:30:52 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:26:35 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:26:34 Warning (5) Dynamic Range Window violation
2019-08-25, 18:26:34 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:26:34 Warning (5) Dynamic Range Window violation
2019-08-25, 18:26:34 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:26:34 Warning (5) Dynamic Range Window violation
2019-08-25, 18:26:34 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;
2019-08-25, 18:26:34 Warning (5) Dynamic Range Window violation
2019-08-25, 18:26:34 Warning (5)

RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=78:d2:94:5a:ec:f8;CMTS-MAC=00:01:5c:ae:d6:68;CM-QOS=1.1;CM-VER=3.1;

 

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 30 681000000 Hz -0.4 dBmV 42.0 dB 1048670649 194 597
2 Locked QAM256 6 537000000 Hz -0.2 dBmV 43.0 dB 1044667119 329 725
3 Locked QAM256 7 543000000 Hz -0.3 dBmV 43.0 dB 1044644260 223 644
4 Locked QAM256 8 549000000 Hz -0.2 dBmV 43.0 dB 1044620271 319 670
5 Locked QAM256 9 555000000 Hz -0.4 dBmV 42.8 dB 1044660530 317 680
6 Locked QAM256 10 561000000 Hz -0.2 dBmV 43.0 dB 1044701070 268 610
7 Locked QAM256 11 567000000 Hz -0.4 dBmV 42.7 dB 1044711729 257 667
8 Locked QAM256 12 573000000 Hz -0.7 dBmV 42.6 dB 1044724341 290 594
9 Locked QAM256 13 579000000 Hz -0.5 dBmV 42.7 dB 1044724935 219 651
10 Locked QAM256 14 585000000 Hz -0.8 dBmV 42.4 dB 1044734981 259 633
11 Locked QAM256 15 591000000 Hz -0.7 dBmV 42.4 dB 1044745174 278 619
12 Locked QAM256 16 597000000 Hz -0.4 dBmV 42.6 dB 1044727550 267 552
13 Locked QAM256 17 603000000 Hz -0.4 dBmV 42.3 dB 1044749308 276 632
14 Locked QAM256 18 609000000 Hz -0.3 dBmV 42.6 dB 1044758921 236 648
15 Locked QAM256 19 615000000 Hz -0.6 dBmV 42.4 dB 1044783428 271 588
16 Locked QAM256 20 621000000 Hz -0.5 dBmV 42.3 dB 1044814987 277 632
17 Locked QAM256 21 627000000 Hz -0.4 dBmV 42.3 dB 1034843174 259 626
18 Locked QAM256 22 633000000 Hz -0.7 dBmV 42.0 dB 1034878154 293 581
19 Locked QAM256 23 639000000 Hz -0.5 dBmV 42.2 dB 1034909038 293 643
20 Locked QAM256 24 645000000 Hz -0.4 dBmV 42.1 dB 1034930679 193 551
21 Locked QAM256 25 651000000 Hz -0.8 dBmV 41.8 dB 1034930849 311 615
22 Locked QAM256 26 657000000 Hz -0.5 dBmV 42.0 dB 1034937789 229 622
23 Locked QAM256 27 663000000 Hz -0.3 dBmV 42.1 dB 1034955477 233 539
24 Locked QAM256 28 669000000 Hz 0.0 dBmV 42.2 dB 1034975141 257 616
25 Locked QAM256 29 675000000 Hz 0.0 dBmV 41.8 dB 1034947744 188 603
26 Locked QAM256 31 687000000 Hz -0.3 dBmV 41.9 dB 1034956842 191 474
27 Locked QAM256 33 693000000 Hz -0.7 dBmV 41.7 dB 1034970805 196 577
28 Locked QAM256 34 699000000 Hz -0.4 dBmV 41.8 dB 1034981330 570 2134
29 Locked QAM256 35 705000000 Hz -0.2 dBmV 41.8 dB 1034929569 1353 728
30 Locked QAM256 36 711000000 Hz -0.4 dBmV 41.6 dB 1034978031 173 539
31 Locked QAM256 37 717000000 Hz -0.3 dBmV 41.6 dB 1034959390 157 450
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 5 17300000 Hz 45.3 dBmV
2 Locked ATDMA 6 23700000 Hz 45.8 dBmV
3 Locked ATDMA 7 30100000 Hz 46.3 dBmV
4 Locked ATDMA 8 36500000 Hz 46.3 dBmV
5 Not Locked Unknown 0 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Hz 0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier Number Range Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked 0 32 780000000 Hz 0.2 dBmV 39.5 dB 1108 ~ 2987 245326588 2 0
2 Not Locked 0 0 0 Hz -0.8 dBmV 0.0 dB 0 ~ 4095 0 0 0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked Unknown 0 0 Hz 0 dBmV
2 Not Locked Unknown 0 0 Hz 0 dBmV
Expert

Re: Signal loss... RNG-RSP CCAP, T3 Timeout, etc

Levels are o/k. Is this 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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Regular Visitor

Re: Signal loss... RNG-RSP CCAP, T3 Timeout, etc

The "No Ranging Response received - T3 time-out", etc.,  are in the modem log, not the connected device. A healthy system should not be generating T3 & T4 timeouts as well as the other present errors.

 

But to answer your question- no, I never lose LAN connectivity with the router over either wifi or ethernet, nor with the modem with the excpetion of when it reboots itself.

Expert

Re: Signal loss... RNG-RSP CCAP, T3 Timeout, etc

I know where RF errors are generated and displayed.. 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.



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Regular Visitor

Re: Signal loss... RNG-RSP CCAP, T3 Timeout, etc

Thank you very much! I'm sure you do; I was just confused by your suggestion to check the wifi Smiley Wink

 

This issue had happened before, a few years ago; they replaced the drop and all was well, turns out the cable had water damage between the insulation and the inner sheath. We have not had any issues thereafter and have been running this hardware setup for almost a year now.

 

Could upgrading to gigabit possibly cause this? 

What about a firmware update to the modem? 

Expert

Re: Signal loss... RNG-RSP CCAP, T3 Timeout, etc


@cds333 wrote:

I was just confused by your suggestion to check the wifi Smiley Wink

 

The process of elimination. Two birds with one stone.

 

Could upgrading to gigabit possibly cause this? 

 

The faster the speeds, the more it is that deficiencies rear their ugly head / the more critical is the need for pristine conditions.

 

What about a firmware update to the modem? 

 

The Comcast system automatically keeps the manufacturer's firmware loads up to date.


 



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Highlighted
Official Employee

Re: Signal loss... RNG-RSP CCAP, T3 Timeout, etc

Good afternoon, cds333. Thanks for posting! I understand the connectivity issue you're experiencing must be frustrating and it's definitely something we'd like to look into for you. I can check some additional diagnostics and information from your modem on this end, to see if we can narrow down the potential cause for the issue. Please send me a private message with your name (first and last) and we can continue from there.

 

To send a private message, please click my name "ComcastMorgan" then select "Send a Message" on the right side.

 

Thank you.  


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