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jarred
join:2014-02-27
Amelia, OH

jarred

Member

[Internet] WAN port flapping frequently causing outages

This started about a week (maybe two) ago. It seems to happen mostly in the morning hours (this morning 4AM-8AM). I wake up, check my phone and find that there is no service on WiFi. I check my router (Mikrotik R750G) and see that the WAN interface went up and down over and over through the early to mid morning hours.

I have called TWC and they constantly blame my equipment, fine perhaps that's the case. Until this morning, where the cable modem (SB 6120) could not train to save its life. I have a tech coming out tomorrow but I wanted to do my due diligence and post here as well to see if there are any recommendations.

The techs I speak with always tell me everything looks great on the cable modem, except for today when they couldn't reach it at all. Here is a readout from the signal page on the modem.

---------------------------------
Upstream Bonding Channel Value
Channel ID 25
Frequency 23000000 Hz
Ranging Service ID 6830
Symbol Rate 2.560 Msym/sec
Power Level 42 dBmV
Upstream Modulation [3] QPSK
[2] 16QAM
[3] 64QAM

Ranging Status Success
-----------------------------------

The logs page shows several errors :
----------------------------------------------------------------------------
Feb 27 2014 08:08:43 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:35:45 6-Notice I401.0 TLV-11 - unrecognized OID;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:35:45 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:35:29 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:35:05 5-Warning T203.0 MDD message timeout;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:50 6-Notice I401.0 TLV-11 - unrecognized OID;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:50 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:39 5-Warning D04.1 ToD request sent - No Response received;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:34 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:14 3-Critical I02.0 REG RSP not received;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:14 4-Error I271.0 T6 Timeout and retries exceeded;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:02 6-Notice I401.0 TLV-11 - unrecognized OID;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:34:02 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:33:56 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:01 5-Warning D04.1 ToD request sent - No Response received;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:19 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:13 6-Notice Cable Modem Reboot due to bonding recovery ;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:33:02 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:33:02 6-Notice DS Partial Service Recovery: CM in DOCSIS 3.0;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
Feb 27 2014 07:32:57 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:22:10:39:0a:bd;CMTS-MAC=00:30:b8:d7:ba:03;CM-QOS=1.1;CM-VER=3.0;
----------------------------------------------------------------------------
(sorry for the mass block of text)

Does anyone see any stand out problems or do signals/etc seem ok?

mackey
Premium Member
join:2007-08-20

mackey

Premium Member

That looks pretty bad. Might be a downstream signal problem; what are the downstream levels? (you only posted the upload levels)

/M
jarred
join:2014-02-27
Amelia, OH

2 edits

jarred

Member

Good question .. good question. They are all blank on the signals page. Upstream is the only table reporting data.

OK rebooted the modem and now I am getting fresh stats :

Downstream Bonding Channel Value
Channel ID 8 5 6 7
Frequency 825000000 Hz 807000000 Hz 813000000 Hz 819000000 Hz
Signal to Noise Ratio 36 dB 35 dB 35 dB 36 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 6 dBmV 6 dBmV 7 dBmV

------------------------------------------------------------
Upstream Bonding Channel Value
Channel ID 25 27
Frequency 23000000 Hz 35000000 Hz
Ranging Service ID 6867 6867
Symbol Rate 2.560 Msym/sec 5.120 Msym/sec
Power Level 42 dBmV 44 dBmV
Upstream Modulation [3] QPSK
[2] 16QAM
[3] 64QAM
[3] QPSK
[3] 64QAM

Ranging Status Success Success

--------------------------------------------
Signal Stats (Codewords) Bonding Channel Value
Channel ID 8 5 6 7
Total Unerrored Codewords 3570702 3570866 3570791 3570797
Total Correctable Codewords 31 71 36 34
Total Uncorrectable Codewords 1770 1492 1604 1601
jarred

jarred

Member

So my connection is starting to flake out again and I am seeing reduced signal quality at this time ..

Downstream Bonding Channel Value
Channel ID 8 5 6 7
Frequency 825000000 Hz 807000000 Hz 813000000 Hz 819000000 Hz
Signal to Noise Ratio 30 dB 29 dB 29 dB 30 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
12 dBmV 11 dBmV 11 dBmV 11 dBmV

SNR has had an average or 5-6 dB loss within a few hours, which I cannot imagine as being acceptable. Also the signal stats (codewords) for uncorrectable have increased drastically.

DocDrew
How can I help?
Premium Member
join:2009-01-28
SoCal

DocDrew

Premium Member

Do you have an amp installed in your home?

The downstream levels are high for such a low SNR (which should be over 33 dB. 30 and under doesn't really work with 256 QAM channels).
jarred
join:2014-02-27
Amelia, OH

jarred

Member

said by DocDrew:

Do you have an amp installed in your home?

The downstream levels are high for such a low SNR (which should be over 33).

I do not.

DocDrew
How can I help?
Premium Member
join:2009-01-28
SoCal
Ubee E31U2V1
Technicolor TC4400
Linksys EA6900

DocDrew

Premium Member

said by jarred:

said by DocDrew:

Do you have an amp installed in your home?

The downstream levels are high for such a low SNR (which should be over 33).

I do not.

Call tech support. Have them send a tech out. I'm guessing something is wrong with the local distribution system, but they'll have to check house wiring first and the signals at the distribution tap.
jarred
join:2014-02-27
Amelia, OH

jarred

Member

said by DocDrew:

said by jarred:

said by DocDrew:

Do you have an amp installed in your home?

The downstream levels are high for such a low SNR (which should be over 33).

I do not.

Call tech support. Have them send a tech out. I'm guessing something is wrong with the local distribution system.

OK cool, one is coming out tomorrow .. just wanting to make sure this gets resolved since I work from home frequently.

DocDrew
How can I help?
Premium Member
join:2009-01-28
SoCal
Ubee E31U2V1
Technicolor TC4400
Linksys EA6900

DocDrew

Premium Member

said by jarred:

OK cool, one is coming out tomorrow .. just wanting to make sure this gets resolved since I work from home frequently.

If it's a distribution system issue, it'll take a few days as they'll need to schedule a second appointment for a maintenance tech to check the distribution system after the service tech checks the house wiring and signal.
jarred
join:2014-02-27
Amelia, OH

jarred

Member

said by DocDrew:

said by jarred:

OK cool, one is coming out tomorrow .. just wanting to make sure this gets resolved since I work from home frequently.

If it's a distribution system issue, it'll take a few days as they'll need to schedule a second appointment for a maintenance tech to check the distribution system after the service tech checks the house wiring and signal.

I'll be interested to find out what the problem is. The chat rep I was logging this info with for some odd reason would not believe that I was getting the information from the modem, he kept telling me that the interface was disabled to customers. When I asked him if he was calling me a liar he dropped the topic and finally just logged the details.

Anyways, the interesting thing to note is that all during the day the service was A-OK, it is when night starts to fall that the service degrades like this.

DocDrew
How can I help?
Premium Member
join:2009-01-28
SoCal
Ubee E31U2V1
Technicolor TC4400
Linksys EA6900

DocDrew

Premium Member

said by jarred:

Anyways, the interesting thing to note is that all during the day the service was A-OK, it is when night starts to fall that the service degrades like this.

When it gets cooler, the cable has less signal loss. This can cause problems after a long distance of cable and more than a couple of distribution amps if not compensated for. The distribution amps usually have "auto gain controls" which should adjust the output signal strength and don't screw up the inputs to the next amp. If those AGCs are off or misadjusted for the temp variation it can cause outputs to vary more than desired. If the inputs to the next amp are too high or too low, distortion or noise is added to the output signal and your SNR and/or BER drops even if the signal strength seems about the same.

Temp variation can also expose faults in the cable system due to expansion and contraction of the cable. Cable cracks, short center conductors, and loose connectors can cause similar issues to above, since they can cause wide signal fluctuations.
jarred
join:2014-02-27
Amelia, OH

jarred

Member

said by DocDrew:

said by jarred:

Anyways, the interesting thing to note is that all during the day the service was A-OK, it is when night starts to fall that the service degrades like this.

When it gets cooler, the cable has less signal loss. This can cause problems after a long distance of cable and more than a couple of distribution amps if not compensated for. The distribution amps usually have "auto gain controls" which should adjust the output signal strength and don't screw up the inputs to the next amp. If those AGCs are off or misadjusted for the temp variation it can cause outputs to vary more than desired. If the inputs to the next amp are too high or too low, distortion or noise is added to the output signal and your SNR and/or BER drops even if the signal strength seems about the same.

Temp variation can also expose faults in the cable system due to expansion and contraction of the cable. Cable cracks, short center conductors, and loose connectors can cause similar issues to above, since they can cause wide signal fluctuations.

Great detail, thank you! This is probably what is going on because here in Cincinnati we have had an extremely cold winter which is out of the norm for us.

My signal states for uncorrectable codewords is going through the roof right now :

Signal Stats (Codewords) Bonding Channel Value
Channel ID 8 5 6 7
Total Unerrored Codewords 33193160 16524434 22587749 30740351
Total Correctable Codewords 2655734 15182090 11548060 4942393
Total Uncorrectable Codewords 81535 4223984 1794834 248016
jarred

jarred

Member

Tech called me today, said the local head end is having problems and it's a known issue. They have no clue when it will be resolved ... apparently that is acceptable to time warner that I continue to pay for service they can't provide.

Their tech support wants to troubleshoot my home equipment again. I swear this company boggles my mind.