Connection Loss

[J-Ho]

Hi all,

I'm in London (SW11) and I've seen some serious connection degradation over the last month, especially in the evenings. I contacted Tech Support on the newsgroups who said the UBR was oversubscribed and that relief work was scheduled for 8th Dec. Yesterday, however the connection dropped altogether and has not restored. I rang Tech Support and booked a technician, but the earliest I will be able to get one is a week away!

So, I was wondering if I could get some help in diagnosing the issue?! Modem is an Ambit 256 on 10Mb connection, sync light stays solid but the ready light flashes. I should note that the TV service has remained fine.

Downstream:

Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -21.3 dBmV
Downstream SNR : 29.9 dB

Upstream:

Upstream Lock : Not Locked
Upstream Channel ID : 2
Upstream Frequency : 37500000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 27.0 dBmV
Upstream Mini-Slot Size : 2


Log:
First TimeLast TimePriorityDescription
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedTime Not EstablishedInformation (7)MAP w/initial maintenance region received
Time Not EstablishedTime Not EstablishedInformation (7)Beginning initial ranging...
Time Not EstablishedTime Not EstablishedError (4)No initial ranging response from CMTS.
Time Not EstablishedTime Not EstablishedCritical (3)Init RANGING Critical Ranging Request Retries exhausted




Also, on the Operation Config page, the Network Access line says "Denied"! However, I'm not sure if that's due to the connection issue.

Any help would be greatly appreciated!

Cheers.

[Joxer]

Your downstream power level is way too low the upsrteam is not much better, SNR is not so great either - you need the tech unless it's a fault on the UBR in which case in may get fixed sooner.

[J-Ho]

Ok, so I replaced all the coax cables internal to the house up to the modem this morning and now have the following:

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -6.9 dBmV
Downstream SNR : 35.2 dB

Cable Modem Upstream
Upstream Lock : Not Locked
Upstream Channel ID : 3
Upstream Frequency : 42800000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 61.0 dBmV
Upstream Mini-Slot Size : 2


With the same errors in the log, sync light still solid, ready flashing. Aren't these power levels now reasonable?

It seems like a bit of a coincidence, but there were Virgin Media vans in the street yesterday, laying new cable.... somebody touched something they shouldn't have?!

[moaningmags]

Your upstream power level at 61.0dbmv will be causing this issue.