Cable modem resets every minute

[robt]

Hello,

I'm based in Swindon and have a 2Mb connection. For the past five weeks or so my ntl:home 120 cable modem has gone through long periods (several hours) when it has continually reset itself approximately every minute. This has happened on most evenings. I get about 20 seconds of internet connectivity, then all the lights apart from the PWR light go out, and I get the modem going through its reset sequence with the rippling lights.

On the odd occasion when I have been at home during the day it doesn't seem to be so bad, though it's not completely a "works during the day but not during the evenng" thing. On some evenings it has worked okay, and I've had the odd problem during the day. I've had evenings where I've switched it on at 6 o'clock, and it has reset itself continually for the next 3 or 4 hours, then all of a sudden it's okay at, say 9 or 10 o'clock.

Three or so weeks ago I called out an NTL engineer, and, Sod's Law being what it is, while he was here (during the morning) the modem worked perfectly. Given that, there was little he could do.

I'm at the point where I'm going to call Tech Support again and get another engineer out. Hopefully, even if it doesn't exhibit the problem while he's here, I can persuade him to give me another modem.

Am I right in thinking that this is likely to be a modem issue? Alternatively, maybe it's an intermittent problem with the part of the network that goes to my house. My neighbour across the road who also has NTL has no such problem. I have NTL cable TV and have no problems with that.

The cable modem problem exists even when everything else (router, PC, etc) is switched off.

Cheers,

Rob

[Aragorn]

to CF

The NTL 120 modems have an event log.

The admin page is at http://192.168.100.1/ and Robin Walkers page explains how to view the logs. That 'might' give you a clue.

It might be the modem, but could also be power levels.

[robt]

Thanks for your prompt reply Aragorn. I've looked at Robin's page and cannot see any way to get an Event Log from the modem admin screen. Down the left hand side I get:

Configuration
Status
Operation Configuration

At the top I see four clickable items:

Cable Modem Information
Set Search Frequency Parameters
Set Ethernet Type
Change Username and Password

I've visited all these screens (and their sub-screens) and there's no logging option anywhere. (I also don't get the "Interface Rate" screen that he mentions.)

On the Configuration screen I get:

Type : Ambit ETH/USB Combo Cable Modem
Cable modem : Ambit Cable Modem
MAC address : xx:xx:xx:xx:xx:xx
IP address : yyy.yyy.yyy.yyy
Downstream Receive Power Level : 1.34 dBmv
Downstream SNR : 32.73 dB
Upstream Transmit Power Level : 42.00 dBmv

On "Operation Configuration" I get:

Network Access : Enabled
Maximum Downstream Data Rate : 2048000 bps
Maximum Upstream Data Rate : 200000 bps
Maximum Number of CPEs : 1
Software Upgrade File Name : ntlhm120_ntl0001.cpr
Software Upgrade AdminStatus : allowProvisioningUpgrade
Software Upgrade OperStatus : completeFromProvisioning

Cheers,

Rob

[Aragorn]

My mistake - Robin's page does say not all modems have all the screens - mine doesn't have the log either.

However, judging by this sticky on power levels, Downstream Recieve looks lowish and the SNR is slightly below the recommended (see the edit at end of Ignition's post).
Anyone more familiar with power levels care to comment?
It might be worth checking the levels again when you next have the issue.

HTH

[robt]

Thanks - the modem was resetting continually this evening from 7pm to around 9pm, then after that it's been working okay.

Here are the current levels:

Upstream Frequency : 33584000 Hz
Upstream Transmit Power Level : 42.00 dBmv

Downstream Lock : Locked
Downstream Frequency : 402750000 Hz
Downstream Modulation : 64 QAM
Downstream Receive Power Level : 1.33 dBmv
Downstream SNR : 32.83 dB

Rob