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Random Packet Loss and No Ranging Response received - T3 time-out

New Poster

Random Packet Loss and No Ranging Response received - T3 time-out

Been noticing my Discord gets robotic the last week or so and that I get hitches/lag in some games.  Decided to run a few ping tests and noticed I'm dropping packets randomly.  Nothing crazy, but 4-6% on longer ping tests.  Decided to look at my modem's logs and noticed some problems.  See below.

 

Model Name: SB6121
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.16-SCM00-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.18m3
Hardware Version: 5.0
Serial Number: 359079207221493301012019
Firmware Build Time: Feb 16 2016 11:28:04

 

Downstream     Bonding Channel Value
Channel ID     30      21      22      23
Frequency     657000000 Hz     603000000 Hz     609000000 Hz     615000000 Hz
Signal to Noise Ratio     37 dB     37 dB     37 dB     37 dB
Downstream Modulation     QAM256     QAM256     QAM256     QAM256
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
    7 dBmV      5 dBmV      5 dBmV      6 dBmV  

Upstream     Bonding Channel Value
Channel ID     2      3      1
Frequency     29400000 Hz     23000000 Hz     35800000 Hz
Ranging Service ID     13382     13382     13382
Symbol Rate     5.120 Msym/sec     5.120 Msym/sec     5.120 Msym/sec
Power Level     41 dBmV     40 dBmV     40 dBmV
Upstream Modulation     [2] QPSK
[1] 32QAM
[3] 64QAM
     [2] QPSK
[1] 32QAM
[3] 64QAM
     [2] QPSK
[1] 32QAM
[3] 64QAM
 
Ranging Status     Success     Success     Success

Signal Stats (Codewords)     Bonding Channel Value
Channel ID     30      21      22      23
Total Unerrored Codewords     1232311924     1232312245     1232312335     1232312490
Total Correctable Codewords     16     0     0     0
Total Uncorrectable Codewords     664     505     554     537

 

Feb 02 2018 08:46:27     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 06:34:06     3-Critical     R06.0     Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 06:34:06     3-Critical     R03.0     Ranging Request Retries exhausted;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 06:34:04     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 01:55:44     5-Warning     Z00.0     MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:12:18     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:14     6-Notice     N/A     Cable Modem Reboot due to T4 timeout ;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 01:42:57     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 01:39:43     5-Warning     T202.0     Lost MDD Timeout;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 01:39:19     3-Critical     T05.0     SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 02 2018 01:33:17     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 01 2018 23:38:41     5-Warning     Z00.0     MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:23     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:14     6-Notice     N/A     Cable Modem Reboot due to power reset ;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Feb 01 2018 23:34:34     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Feb 01 2018 23:01:58     5-Warning     Z00.0     MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:20     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=a4:7a:a4:6d:3d:ae;CMTS-MAC=00:01:5c:71:9e:55;CM-QOS=1.1;CM-VER=3.0;

Expert

Re: Random Packet Loss and No Ranging Response received - T3 time-out

The stats as read at the modem level at that moment in time were o/k but there are three additional signal stats that can cause problems which can't be read by the modem. They can only be read from their end by them polling the CMTS (Cable Modem Termination System) at the local headend facility.

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.

You can call in and ask what these figures are. The Upstream Receive Power Level should fall within the range of -2dB to +2dB with 0dB being in the middle and perfect.

The Upstream SNR should be least 31dB, and the higher it is the better.

The ICFR should be no higher than 2 dB.

You could have an intermittent noise ingress issue in only the upstream channel(s) / return path only somewhere.

They will be able to see whether or not everything is in the green zone and also see a history plot for the modem.


New Poster

Re: Random Packet Loss and No Ranging Response received - T3 time-out

Thank you for the info! I have a call scheduled with one of their techs today so it's great to know basically exactly what to ask for.  Is there a possiblity that this is just my modem going bad/failing?

Expert

Re: Random Packet Loss and No Ranging Response received - T3 time-out

Anything is "possible" of course. But it is more likely to be a line / system problem. Good luck !

Admin1

Re: Random Packet Loss and No Ranging Response received - T3 time-out

Hi Seppic -- Checking in to see if the tech was able to help with your packet loss issue.