Modem Keeps Losing Connection

[dannyboy20]

Hi, I have been with Virgin for years and never really had any problems. But the past week or 2 I have been losing connection to the net at random times. I'm on 20mb and the modem is in the other room. When I look the Power and Receive lights are on but the Send light is flashing. I turn the modem off by the power and 5 mins later it usually connects.

Tonight it lost connection about 5 times in an hour. I really don't know why as i've never had a problem before.

Any ideas? I'm in the West Midlands area.

[Zhadnost]

First check http://status-cable.virginmedia.com/vmstatus/summary.do to see if it's a reported issue.

Then I'd post a support enquiry on virginmedia.support.broadband.cable. (details are at http://www.virginmedia.com/myvirginmedia/newsgroups/ )

Include times of day and duration of outages.

The downstream and upstream statistics from the Cablemodem obtained by visiting 192.168.100.1 (username/password is root/root). Do not include MAC address or serial number.

The Log obtained from the modem on 192.168.100.1.

Response times during office hours are typically around 20 minutes (although can be a bit longer).

[mswhite]

I wonder whether this is the same problem I have been having - see Virgin Media Internet Services/Intermittent Connection. Apparently due to the system being overloaded.

[dannyboy20]

Thanks for the advice Zhadnost, ill send them a support query when i get home. Theres no issues in my area.

I've been told that someone may have cloned my MAC address, and are on the same UBR which is causing the modem to lose sync.

If this is the case, i'm guessing I need my modem changed?

[Peter_]

Thanks for the advice Zhadnost, ill send them a support query when i get home. Theres no issues in my area.

I've been told that someone may have cloned my MAC address, and are on the same UBR which is causing the modem to lose sync.

If this is the case, i'm guessing I need my modem changed?
Usually it is another customer with the same MAC address on their NIC that causes this kind of issue so have Virgin told you which MAC address it is thats the issue here, is it the Modem MAC address or the NIC MAC address.

[dannyboy20]

It was just a suggestion someone made on another forum, I haven't contacted VM yet, as i'm at work.

[moaningmags]

If you're losing connection resulting in a solid power and receive light but flashing send light, I'd be checking your upstream power level. If out of acceptable levels I'd book a tech for recurring intermittent connection caused by fluctuating power levels.

When you lose the connection, open your browser and go to the following
http://192.168.100.1 click on signal and take note of the upstream power level.
Less than 34dbmv or more than 56dbmv, you'll be needing a tech.

[Peter_]

It was just a suggestion someone made on another forum, I haven't contacted VM yet, as i'm at work.
What sometimes happens is that 2 people buy different computers and both have the same MAC on their NIC and by chance they can be on the same uBR so whoever gets a connection first stops the other person getting on the net, usually a quick fix is using a router or swapping the NIC or if confident changing the MAC address on the NIC itself.

Of course this may not be the fault and you will find out when you call later.

[dannyboy20]

If you're losing connection resulting in a solid power and receive light but flashing send light, I'd be checking your upstream power level. If out of acceptable levels I'd book a tech for recurring intermittent connection caused by fluctuating power levels.

When you lose the connection, open your browser and go to the following
http://192.168.100.1 click on signal and take note of the upstream power level.
Less than 34dbmv or more than 56dbmv, you'll be needing a tech.

I did a check yesterday when I posted on another forum, my upstream seemed fine. Its around 43.0 dBmV

My downstream is around 6.0 dBmV

[weesteev]

Hi Danny

If you want me to check this issue for you then drop me a PM with your details. The issue may be high utilisation in your area.

You mention that the modem is in a different room though, are you connected wirelessly or by homeplug adapters? Have you tried direct connecting to the modem to see if you get the same issues?

[Ignitionnet]

FWIW This is a handy link for decoding what those flashing lights on the modems mean:

http://broadband.modemhelp.net/cable_modem_info/ambit/U10C018.shtml

As far as the utilisation thing goes they are not the same issue, having the connection be 'stuttery' compared with a total loss of connection are different issues and downstream congestion, which is causing the issues in the other thread, cannot cause loss of connectivity. Only extreme upstream congestion may cause total loss of connection and there's nowhere on the VM network which is congested upstream to that extent (upstream speeds too naff to stress that bandwidth).

It would be useful to get a couple of things though.

Is there anything in your modem's status logs? Any Timeouts or similar? Can you check the log next time it happens and copy/paste it before you reboot please.

Other than that the MAC address conflict is unlikely but possible.

[dannyboy20]

It went off again a while ago. Its been off for about 30 minutes. Here's a snippet of the log:

2009-04-10 19:21:07 3-Critical R003.0 Init RANGING Critical Ranging Request (17) Retries exhausted
2009-04-10 19:21:07 3-Critical R002.0 No Ranging Response received - T3 time-out (US 4)
2009-04-10 19:20:28 6-Notice M572.0 T4 No Station Maint Timeout - Reinitialize MAC...
2009-04-10 19:20:28 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o
2009-04-10 19:19:56 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out


Also this was in the log quite a lot:

1970-01-01 00:22:43 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
1970-01-01 00:22:37 6-Notice M572.0 Ds Lock Failed - Reinitialize MAC...

[moaningmags]

Did you take note of the upstream power level at the time it was off?

[dannyboy20]

Yes it dropped to 14 dBmV.

I sent a support ticket to VM and they're sending a replacement modem so we'll see how that goes.

[graf_von_anonym]

A new modem isn't likely to do much for you, but we'll see. Upstream power dropping that low usually requires a technician to visit.

[dannyboy20]

Just an update on this, I received the new modem last week, after 2 days of downtime (modem not registered, VM promising to ring back etc) it finally came on and my connection has been fine since. Its an Ambit modem I received to replace my old SB5101.