techlee's profile

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2 Messages

Tuesday, May 5th, 2020 3:00 PM

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Internet keeps disconnecitng

Dear helpdesk,

 

Recently my internet disconnecting again and again, especially since the pandemic (around a month ago).

Restarting modem or router didn't help at all,

Could anyome help me to figure out?

 

Below are the log messages from my modem:

=============================================================

Time Priority Description
2020-5-5, 15:50:48 Warning (5) Unicast DSID PSN startup error
2020-5-5, 15:48:56 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-5-5, 15:48:41 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:17:24 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-5-5, 15:17:13 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-5-5, 15:17:12 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-5-5, 15:17:02 Warning (5) Lost MDD Timeout;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2020-5-5, 15:16:50 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.0;CM-VER=3.0;
2020-5-5, 15:16:47 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:16:30 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:16:13 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-5-5, 15:15:53 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.0;CM-VER=3.0;
2020-5-5, 15:15:50 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:15:33 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:15:19 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-5-5, 15:15:06 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.0;CM-VER=3.0;
2020-5-5, 15:15:03 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:14:46 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:14:28 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2020-5-5, 15:14:13 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:bf:d4:40;CMTS-MAC=d4:2c:44:7d:82:ae;CM-QOS=1.1;CM-VER=3.0;
2020-5-5, 15:10:29 Notice (6) Honoring MDD; IP provisioning mode = IPv6

=========================================================================

Expert

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110.1K Messages

5 years ago

You need to post the signal status figures as well. 

 

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

What is the exact make and model number of the modem ?

Is this a WiFi connection ?

New Poster

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2 Messages

5 years ago

Thank you for the reply. 

 

I use both ethernet and wifi, and both of them didn't work.

 

Below are the downstream, upstream, and SNR (internet is working now, so the status could be differ from the abnormal state?): 

 

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 579000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD honorMdd(4)

 

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 21 579000000 Hz 6.9 dBmV 40.2 dB 0 0
2 Locked QAM256 13 531000000 Hz 6.2 dBmV 40.4 dB 0 0
3 Locked QAM256 14 537000000 Hz 5 dBmV 40 dB 0 0
4 Locked QAM256 15 543000000 Hz 4.5 dBmV 39.8 dB 0 0
5 Locked QAM256 16 549000000 Hz 4.8 dBmV 40 dB 0 0
6 Locked QAM256 17 555000000 Hz 5.9 dBmV 40.1 dB 0 0
7 Locked QAM256 18 561000000 Hz 5.2 dBmV 40 dB 0 0
8 Locked QAM256 19 567000000 Hz 5.1 dBmV 39.8 dB 0 0
9 Locked QAM256 20 573000000 Hz 6 dBmV 40 dB 0 0
10 Locked QAM256 22 585000000 Hz 6.1 dBmV 40.1 dB 0 0
11 Locked QAM256 23 591000000 Hz 5.8 dBmV 40.1 dB 0 0
12 Locked QAM256 24 597000000 Hz 6.6 dBmV 40.2 dB 0 0
13 Locked QAM256 25 603000000 Hz 6.6 dBmV 40.2 dB 0 0
14 Locked QAM256 26 609000000 Hz 5.8 dBmV 40 dB 0 0
15 Locked QAM256 27 615000000 Hz 5.1 dBmV 39.7 dB 0 0
16 Locked QAM256 28 621000000 Hz 6.4 dBmV 40 dB 0 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 2 5120 Ksym/sec 30100000 Hz 57 dBmV
2 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
3 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
4 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV

 

Modem is Netgear CM500-100NAS

 

 

Expert

 • 

110.1K Messages

5 years ago

The upstream power is out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

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