Basic Internet Connectivity And Modem Help

[DirtyRed1225]

For about a month my SB6120 has been rebooting. I have recorded multiple reboots per day. Each time the reboot happens it takes many minutes, sometimes upwards to an hour for the internet connectivity to work again. I am at my wits end! 

A Comcast tech has been out once, and as the usual goes could find nothing wrong with the signal inside the house. 

My thought is that the signal is out of allignment (or whatever one might call it) outside of my house. 

Here are the signal specs on the my SB6120.

Please help out if you can and let me know if my signal specs are appropriate to my modem.

I am looking for some more info that I can use when talking to the Comcast service reps and techs. Any help would be greatly appreciated.

Channel ID                                                        2                   3                    5                   7 

Frequency                                                          693000000 Hz                   699000000 Hz   711000000 Hz                                                                            723000000 Hz 

Signal to Noise Ratio                                         37 dB           38 dB            38 dB           38 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

                                                                           0 dBmV       0 dBmV        0 dBmV       0 dBmV  

Channel ID                     11                            12 

Frequency                       36400000 Hz          29500000 Hz 

Ranging Service ID        562                          562 

Symbol Rate                   5.120 Msym/sec      2.560 Msym/sec 

Power Level                    54 dBmV                54 dBmV 

Upstream Modulation     [3] QPSK
[3] 64QAM
                                        [3] QPSK
[2] 16QAM
 

Ranging Status               Success                    Success 

Signal Stats (Codewords)             Bonding Channel Value

Channel ID                                     2                      3                      5                      7 

Total Unerrored Codewords          262692129      261016436      261016526      261016352 

Total Correctable Codewords        0                      1                      0                      0 

Total Uncorrectable Codewords    1361                1408                1456                1425 

[EG]

The upstream power is too high and may be intermittently fluctuating even higher out of spec.That will indeed cause random disconnects and spontaneous re-booting of the modem. Are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured ?

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 putting them back together again, then perhaps it's best to book a tech visit to investigate and correct.

[DirtyRed1225]

Thank you. Additionally here are my modem's logs. Perhaps this will shed more light on the problem.

Time

Priority

Code

Message

Aug 06 2012 08:16:23

6-Notice

I401.0

TLV-11 - unrecognized OID;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:16:23

5-Warning

Z00.0

MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Jan 01 1970 00:00:36

3-Critical

R02.0

No Ranging Response received - T3 time-out;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Jan 01 1970 00:00:13

6-Notice

N/A

Cable Modem Reboot due to T4 timeout ;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:15:18

3-Critical

R04.0

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:14:48

3-Critical

R02.0

No Ranging Response received - T3 time-out;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:14:46

3-Critical

R06.0

Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:14:46

3-Critical

R03.0

Ranging Request Retries exhausted;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:14:46

3-Critical

R02.0

No Ranging Response received - T3 time-out;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:49

6-Notice

I401.0

TLV-11 - unrecognized OID;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:49

5-Warning

Z00.0

MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Jan 01 1970 00:00:13

6-Notice

N/A

Cable Modem Reboot due to T4 timeout ;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:06

3-Critical

R06.0

Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:06

3-Critical

R03.0

Ranging Request Retries exhausted;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:05

3-Critical

R02.0

No Ranging Response received - T3 time-out;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:05

3-Critical

R06.0

Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:05

3-Critical

R03.0

Ranging Request Retries exhausted;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 08:01:04

3-Critical

R02.0

No Ranging Response received - T3 time-out;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 07:18:44

6-Notice

I401.0

TLV-11 - unrecognized OID;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

Aug 06 2012 07:18:44

5-Warning

Z00.0

MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=e4:83:99:8b:6d:8e;CMTS-MAC=00:01:5c:23:00:02;CM-QOS=1.1;CM-VER=3.0;

[EG · Accepted solution]

The T3 and T4 errors do indeed indicate a RF signal / connection quality issue. Perhaps there is some sort of a return path impairment (either the excessive attenuation from connections / splitters mentioned) and / or a noise ingress problem which is making it difficult for the modem and the system to hear and talk to each other.

[DirtyRed1225]

Thank you. I would add that the modem worked flawlessly for nearly a year and then this rebooting issue began. I have added no splitters nor have I modified the wiring in any way. I will disconnect and reconnect the splitters Comcast installed originally to see if it proves to solve my problem. If this does not work then you think a tech should inspect further?

[EG]

That would seem to be your only other option.

[DirtyRed1225]

Would you possibly draw a conclusion as to this problem being connected to a faulty firmware issued out be Comcast? Seeing how my internet connection has been functioning flawlessly for nearly one year with all the same wiring, configuration, and modem, is it probable to think this could be the problem of a bad firmware update sent out by Comcast? I understand the upstream power being too high is the likely cause of my modem frequently rebooting. Is it possible that an inapporpriately configured firmware update by Comcast caused the upstream power to reach to high of a level? 

[EG]

Regardless of the firmware, your signal issue must be addressed by an actual physical intervention.

[andyross]

There are numerous threads about the 6120 and 6121 having issues since Comcast enabled upstream bonding.

As mentioned, your upstream is at 54 for each channel, which is the maximum for two upstream bonded channels. That is probably the biggest issue you need to try fixing first.

Basically, upstream bonding has sharply restricted some of the limits signals can go to. You need cleaner and quieter lines or it will fail. Unfortunately, the infrastructure in many areas is not up to it.

[Andrios]

Wow im having the same exact issue. Mine has been perfect for a year, and now its disconnecting every half hour with same logs as OP.

I told them to send a tech out, I hope he can solve the issue.

Have you solved your issue?

Thanks

[thinkderek]

+1 It's been going on for weeks now.  But this morning was really bad.  So a tech is coming out this Sunday.  Identical looking logs as the ones posted.

Downstream     Bonding Channel Value
Channel ID     2      4      7      8
Frequency     651000000 Hz     663000000 Hz     681000000 Hz     687000000 Hz
Signal to Noise Ratio     37 dB     37 dB     38 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
    0 dBmV      0 dBmV      0 dBmV      0 dBmV  

Upstream     Bonding Channel Value
Channel ID     3      1      2
Frequency     21400000 Hz     36000000 Hz     29600000 Hz
Ranging Service ID     3316     3316     3316
Symbol Rate     2.560 Msym/sec     5.120 Msym/sec     5.120 Msym/sec
Power Level     36 dBmV     40 dBmV     39 dBmV
Upstream Modulation     [3] QPSK
[2] 16QAM
     [3] QPSK
[3] 64QAM
     [3] QPSK
[3] 64QAM
 
Ranging Status     Success     Success     Success

Signal Stats (Codewords)     Bonding Channel Value
Channel ID     2      4      7      8
Total Unerrored Codewords     162995158     162996439     162995106     162995108
Total Correctable Codewords     112     7     243     364
Total Uncorrectable Codewords     2640     1392     2497     2376

[claudewang]

I have exactly the same issue as OP. A comcast technician will come tomorrow. I will post the follow-up/

Here is my modem status:

Channel ID     89      90      91      92
Frequency     681000000 Hz     687000000 Hz     693000000 Hz     699000000 Hz
Signal to Noise Ratio     37 dB     37 dB     38 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
    -1 dBmV      0 dBmV      0 dBmV      -2 dBmV  

Upstream     Bonding Channel Value
Channel ID     2      1
Frequency     36500000 Hz     30100000 Hz
Ranging Service ID     2839     2839
Symbol Rate     5.120 Msym/sec     5.120 Msym/sec
Power Level     54 dBmV     54 dBmV
Upstream Modulation     [3] QPSK
[3] 64QAM
     [3] QPSK
[3] 64QAM
 
Ranging Status     Success     Success

Signal Stats (Codewords)     Bonding Channel Value
Channel ID     89      90      91      92
Total Unerrored Codewords     106228283     105289679     105289944     105290033
Total Correctable Codewords     1     0     0     1
Total Uncorrectable Codewords     543     650     530     593

[EG]

---

claudewang wrote:

Power Level     54 dBmV     54 dBmV

---

Out of spec.

[claudewang]

Hi EG,

Yes, also as some previous people suggested, 54 dbmV for UpStream Bonding seems to be too high. So how can I solve this issue? I don't use any spliter in my house. I don't use comcast TV, but only the internet!

The coaxis cable between my modem and outlet is also new (installed by Comcast technician two years ago).

Please suggest me what else I can do to solve this problem. Thanks a lot.

PS: Now my internet conncect is back, but I don't know when it will be disconnected again due to such issue, perhaps.

Claude.

[EG]

You have a tech coming. Let him take care of it !