09-17-2012 02:51 PM
We are having the same issue here in Brunswick, Maine. Internet is almost unusable. Connection dropping every few minutes. Seems to have gotten worse over the last week.
09-17-2012 03:58 PM
What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1
Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.
09-18-2012 08:27 AM
My modem is at http://10.0.0.1
Downstream Channel Bonding Value
Index 1 2 3 4
Lock Status Locked Locked Locked Not locked
Frequency 692.998 MHz 698.999 MHz 705.001 MHz
SNR 37.936 dB 37.636 dB 37.936 dB
Power 6.457 dBmV 6.532 dBmV 6.015 dBmV
Modulation 256 QAM 256 QAM 256 QAM
Upstream Channel Bonding Value
Index 1 2 3 4
Lock Status Locked Not locked Not locked Locked
Frequency 35800000 Hz 29400000 Hz
Symbol Rate 5120 KSym/sec 5120 KSym/sec
Power Level 37.7500 dBmV 37.7500 dBmV
Modulation 64QAM 64QAM
Channel ID 5 4
09-18-2012 08:30 AM
Here is an excerpt from the logs:
Lost MDD Timeout;CM-MAC=b8:9b:c9:9c:af:70;CMTS-MAC=1c:df:0f
09-18-2012 10:12 AM
The signal stats at the moment in time were in spec. That address looks to be one for a combo modem / gateway device (perhaps an SMC ?) If it is, is it only wireless connections that drop or do hard wired ethernet connections to it drop as well ?
09-18-2012 04:19 PM
The log is one hour off (e.g. it's now 4:16 pm but the log date stamps show 15:16) and full of warnings and critical error messages.
SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=b8:9b:c9:9c:af:70;CMTS-MAC=1c:df:0f:02
No Ranging Response received - T3 time-out;CM-MAC=b8:9b:c9:9c:af:70;CMTS-MAC=1c:df:0
Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=b8:9b:c9:9c:af:70;CMTS-MAC=1c:df:0f:02:
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=b8:9b:c9:9c:af:70;CMTS-MAC=1c:df:0f:02:
09-18-2012 04:27 PM - edited 09-18-2012 04:29 PM
Is it an SMC ? Exact make and model number would be more helpful to both you and I rather than a "one liner" answer ? This may be a firmware problem that we have been seeing here as of late. It may also be a hardware defect. These SMC's are basically junky devices.
If wired connections "drop" as well, then this may indeed be an RF signal / connection quality issue on the Comcast side even though the stats that can be displayed by the modem are in spec. There is more to the story.
There are two additional signal stats which can't be read at the modem level. They can only be read from their end by them polling the CMTS (Cable Modem Termination System) at the local headend facility.
They are the 'Upstream Receive Power Level' and the 'Upstream uSNR' (upstream Signal To Noise Ratio). Both of these are as equally important in diagnosing connectivity issues as are the modem's stats.
You can call in and ask what these figures are. The Upstream Receive Power Level should fall within the range of -10dB to +10dB with 0dB being in the middle and perfect.
The Upstream SNR should be least 30dB, and the higher it is the better. You could have a noise ingress issue in the upstream channel/s (path).
Don't worry about the time. It doesn't affect performance. Modems don't adjust for daylight savings / standard time.
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