Dropping connection most nights

phoenix__ · 07-07-2009, 08:43

Guys,

I've got a 255 Modem on a 20MB service in Colchester, which has been (for the most part) stable for the last several years. Our gateway is a Linux PC running 24/7 and I use the fact that the IP address hardly ever changes to run some services from the machine.

Last week the modem dropped out (all the lights were on, but I had to power cycle the modem to get an IP address out of it) and when it came back I had a completely different IP address, which made me think there has been some network reconfiguration.

This in itself was not a problem, but almost ever night since then I've come down in the morning to find no connectivity without having to ifdown/ifup the connection - on one occasion I had to cycle the power on the modem.

Does anyone have any thoughts or suggestions? Modem status is printed below.

Cheers,
-Jeff

Downstream Lock : Locked
Downstream Channel Id : 69
Downstream Frequency : 299000000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 1.2 dBmV
Downstream SNR : 37.2 dB

Upstream Lock : Locked
Upstream Channel ID : 1
Upstream Frequency : 47400000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 45.5 dBmV
Upstream Mini-Slot Size : 2

Modulation Type QPSK QPSK QPSK 16QAM 16QAM
Differential Encoding Off Off Off Off Off
Preamble Length 64 128 128 144 160
Preamble Value Offset 140 6 6 216 216
FEC Error Correction (T) 0 5 5 5 10
FEC Codeword Information Bytes (k) 16 34 34 78 235
Scrambler Seed 338 338 338 338 338
Maximum Burst Size 2 0 0 8 0
Guard Time Size 8 48 48 8 8
Last Codeword Length Fixed Fixed Fixed Short Short
Scrambler on/off On On On On On

Tue Jul 07 07:37:02 2009 Tue Jul 07 07:37:02 2009 Information (7) Downstream sync ok
Tue Jul 07 07:37:02 2009 Tue Jul 07 07:37:02 2009 Information (7) locked and synced to rescue CMTS...all is well!
Tue Jul 07 07:37:02 2009 Tue Jul 07 07:37:02 2009 Information (7) Downstream sync ok
Tue Jul 07 07:37:01 2009 Tue Jul 07 07:37:01 2009 Information (7) Locked on the rescue CMTS ds. try to re-acquire ds sync...
Tue Jul 07 07:37:01 2009 Tue Jul 07 07:37:01 2009 Information (7) Downstream lock ok
Tue Jul 07 07:37:01 2009 Tue Jul 07 07:37:01 2009 Information (7) Downstream lock failed
Tue Jul 07 07:37:01 2009 Tue Jul 07 07:37:01 2009 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC f...
Tue Jul 07 07:36:59 2009 Tue Jul 07 07:36:59 2009 Information (7) Downstream lock failed
Tue Jul 07 00:50:42 2009 Tue Jul 07 00:50:42 2009 Information (7) Downstream sync ok
Tue Jul 07 00:50:42 2009 Tue Jul 07 00:50:42 2009 Information (7) locked and synced to rescue CMTS...all is well!
Tue Jul 07 00:50:42 2009 Tue Jul 07 00:50:42 2009 Information (7) Downstream sync ok