Bizarre Daily Power Fluctuations

[gurgeh]

Every day at around 11.20 - 12.20 my connection drops. If I attach an attenuator to my modem its fine - until the same time the next day, when I take the attenuator off its fine again and so on.
My current and very helpful engineer has tried changing cables inside and out, attached a booster and changed the modem, all to no avail. He seems convinced its a cabinet problem but his network colleagues disagree.

Any thoughts?

[vmfriend]

Post your modem stats and a friendly helpful person will take a look for you.

[gurgeh]

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 307000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK
Security Enabled BPI+
Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM256 198 55616000 Kbits/sec 307000000 Hz 8.3 dBmV 37.0 dB Hybrid
Locked QAM256 197 55616000 Kbits/sec 299000000 Hz 8.7 dBmV 37.0 dB Hybrid
Locked QAM256 199 55616000 Kbits/sec 315000000 Hz 8.5 dBmV 36.7 dB Hybrid
Locked QAM256 200 55616000 Kbits/sec 323000000 Hz 8.3 dBmV 36.8 dB Hybrid
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Upstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 8 20480 Kbits/sec 45800000 Hz 44.5 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Primary Downstream Service Flow
Downstream(0)
SFID 9766
Max Traffic Rate 10240000 bps
Max Traffic Burst 3044 bytes
Mix Traffic Rate 0 bps
Primary Upstream Service Flow
Upstream(0)
SFID 9575
Max Traffic Rate 1072000 bps
Max Traffic Burst 8160 bytes
Mix Traffic Rate 0 bps
Max Concatenated Burst 8160 bytes
Scheduling Type Best Effort

---------- Post added at 10:23 ---------- Previous post was at 10:22 ----------

Workig fine at the mo. As I say will probs change in an hour or so. Will post new levels if it does.

---------- Post added at 12:07 ---------- Previous post was at 10:23 ----------

Ok just went off as expected.


Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 307000000 Hz Locked
Connectivity State In progress Access Denied
Boot State In progress Unknown
Configuration File OK
Security Disabled Disabled
Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM256 198 55616000 Kbits/sec 307000000 Hz -7.7 dBmV 32.3 dB Hybrid
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Upstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 8 20480 Kbits/sec 45800000 Hz 58.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Current System Time:Sun Sep 25 11:00:57 2011


Put the attenuator on again ad its back on with


Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 315000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK
Security Enabled BPI+
Downstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power SNR Docsis/EuroDocsis locked
Locked QAM256 199 55616000 Kbits/sec 315000000 Hz -1.1 dBmV 35.7 dB Hybrid
Locked QAM256 197 55616000 Kbits/sec 299000000 Hz -1.0 dBmV 35.9 dB Hybrid
Locked QAM256 198 55616000 Kbits/sec 307000000 Hz -1.2 dBmV 35.8 dB Hybrid
Locked QAM256 200 55616000 Kbits/sec 323000000 Hz -1.4 dBmV 35.6 dB Hybrid
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 0.0 dB Unknown
Upstream Channels
Lock Status Modulation Channel ID Max Raw Bit Rate Frequency Power
Locked ATDMA 8 20480 Kbits/sec 45800000 Hz 45.3 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Unlocked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
Primary Downstream Service Flow
Downstream(0)
SFID 3967
Max Traffic Rate 10240000 bps
Max Traffic Burst 3044 bytes
Mix Traffic Rate 0 bps
Primary Upstream Service Flow
Upstream(0)
SFID 10978
Max Traffic Rate 1072000 bps
Max Traffic Burst 8160 bytes
Mix Traffic Rate 0 bps
Max Concatenated Burst 8160 bytes
Scheduling Type Best Effort

[RB2004]

+8 is too high

+7 is the upper limit generally for it to be within specification, and -3 is the lower limit.

but for it to jump from +8 to -7 doesnt seem right.
could indicate a network fault.. best call support and get an engineer.

[Sephiroth]

Might the attenuator be a red herring? i.e. if you were to reboot with the attenuator on would it come back? I'm in no doubt that the attenuator needs to be there.

When it fails, downstream power and SNR drop so that no sense can be made of what's coming down. What does the event log say?

[pabscars]

Acquire Downstream Channel 307000000 Hz Locked
Acquire Downstream Channel 315000000 Hz Locked
Looking above shows the ops DS channel has changed, so could this point to something.

Also agree with Seph that the act of putting the attenuater on is probably just a fluke, I bet it's just the act of physically rebooting the modem that's forcing it to reconnect, but a copy of the event log should help those in the know.

[Sephiroth]

Hi Pabs,

Any DS channel in the pool that is capable of assignment as a Primary channel (through which the rest of initialisation takes place) will be assigned. The remaining channels in the bonding froup have to be within a certain frequency of that. The interchanged Primary channel numbers is not a factor per se.

[pabscars]

Hi Pabs,

Any DS channel in the pool that is capable of assignment as a Primary channel (through which the rest of initialisation takes place) will be assigned. The remaining channels in the bonding froup have to be within a certain frequency of that. The interchanged Primary channel numbers is not a factor per se.

Coolio, I just thought it may have been overlooked,

cheers Seph