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Intermittent connectivity problem: MDD Message Timeout, Started Unicast Maintenance Ranging ..

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Intermittent connectivity problem: MDD Message Timeout, Started Unicast Maintenance Ranging ..

Please advise how to go about this - Symptom is that once or twice a day I lose internet connectivity. I can fix it by simply waiting a few minutes. But with working from home & school from home, that can be pretty disruptive with constant vpn disconnections. So I really want to fix this:

 

Here are the event logs from when it happened this afternoon:

Time Priority Description

Fri Sep 11 16:31:55 2020Warning (5)MDD message timeout;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 15:00:37 2020Warning (5)MDD message timeout;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 12:02:27 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 12:02:27 2020Warning (5)MDD message timeout;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 11:57:24 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 11:57:24 2020Warning (5)MDD message timeout;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 11:52:25 2020Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;
Fri Sep 11 11:52:25 2020Warning (5)MDD message timeout;CM-MAC=e8:6d:52:7a:ab:4c;CMTS-MAC=00:01:5c:6b:f8:52;CM-QOS=1.1;CM-VER=3.0;

 

Downstream Bonded Channels
ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectedUncorrectables
1LockedQAM25633645000000 Hz1.1 dBmV39.6 dB00
2LockedQAM25634651000000 Hz0.4 dBmV39.5 dB00
3LockedQAM25635657000000 Hz0.5 dBmV39.0 dB00
4LockedQAM25636663000000 Hz-0.4 dBmV39.1 dB00
5LockedQAM25638669000000 Hz-0.6 dBmV39.0 dB57888104
6LockedQAM25639675000000 Hz-0.1 dBmV39.0 dB312616277772
7LockedQAM25640681000000 Hz-0.2 dBmV39.0 dB00
8LockedQAM25641687000000 Hz-0.9 dBmV38.6 dB00

 

Upstream Bonded Channels
ChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower
1LockedATDMA75120 Ksym/sec23700000 Hz50.0 dBmV
2LockedATDMA55120 Ksym/sec36500000 Hz48.2 dBmV
3LockedATDMA65120 Ksym/sec30100000 Hz48.2 dBmV
4LockedATDMA85120 Ksym/sec17300000 Hz50.7 dBmV
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Re: Intermittent connectivity problem: MDD Message Timeout, Started Unicast Maintenance Ranging ..

The upstream power is too high and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

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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