Netgear DG834 V4 Keeps dropping off line

[longserpent]

The line is a "BT Business Total Broadband Option 2" with 1 static IP address which was installed back in 2008.

Originally, we were using Netopia modems, but the exchange has been recently updated, and these modems are no longer compatible, so we replaced them with the Netgear DG834 V4's which we have successfully deployed at many other locations around the UK.

The symptom is that after a random period of between 15 minutes and 6 days, the router appears to disconnect from the internet and requires a reboot/power cycle to get it back on.

Thinking it was a hardware fault, we replaced the router with another unit including the cables and micro-filter - no change.

The username/password are as per the original BT emails.

ADSL Settings are; VC-Based, VPI=0, VCI=38

DSL Mode: We have tried - Auto(multi-mode), ADSL2+, G.DMT all with same result.

Router Settings: PPPoA, Never logout, Get IP Dynamically, Get DNS from ISP, NAT enabled.

BT say there is no problem with the line or the exchange, and that its our router at fault. I find that hard to believe considering I have literally dozens of these working with exactly the same hardware/configuration settings at other locations!

Can anyone help? Thanks.

[kuerten]

There should be logs on the netgear device that would give us clues on what's going on. Can you paste some? Specifically on the time that the connection was interrupted. 

[longserpent]

There is nothing unusual in the logs I can see; is there some logs which I can FTP off the device which contain more detail?

Mon, 2012-04-02 14:35:39 - Router start up
Thu, 2012-04-12 14:59:47 - Administrator login successful - IP:

Thu, 2012-04-12 15:04:36 - LCP down.
Thu, 2012-04-12 15:05:30 - Initialize LCP.
Thu, 2012-04-12 15:05:30 - LCP is allowed to come up.
Thu, 2012-04-12 15:05:31 - CHAP authentication success
Thu, 2012-04-12 15:07:17 - Administrator login successful - IP:

Thu, 2012-04-12 15:07:34 - Administrator login successful - IP:
Thu, 2012-04-12 15:14:18 - LCP down.
Thu, 2012-04-12 15:15:07 - Initialize LCP.
Thu, 2012-04-12 15:15:07 - LCP is allowed to come up.
Thu, 2012-04-12 15:15:10 - CHAP authentication success

(IP addresses edited out for obvious reasons) 

BT came in yesterday and told us the line is less than 100m from the exchange, and other than the Noise margin being tweaked to 6db, there wasn't much else they could do.

Interestingly, even though the router seemed to think it was connected to the infernalnet, for some reason we couldn't reach any external sites (e.g. bbc.co.uk); forcing a disconnect and reconnect get it working again.

Lets see what it thinks in the morning!

System Up Time 242:08:54

Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time WAN PPPoA 3214 3656 0 347 1521 00:29:23 LAN 10M/100M 332389 463906 0 43 53 242:08:48

ADSL Link Downstream Upstream Connection Speed 20463 kbps 888 kbps Line Attenuation 16.0 db 6.9 db Noise Margin 6.5 db 15.0 db

[longserpent]

This mornings stats; I note the Tx & Rx B/s has dropped significantly since yesterday afternoon, but I don't know how they measure that.

System Up Time 258:30:55

Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time WAN PPPoA 22351 22783 0 75 105 16:51:24 LAN 10M/100M 337289 477889 0 41 51 258:30:49

ADSL Link Downstream Upstream Connection Speed 20463 kbps 888 kbps Line Attenuation 16.0 db 6.9 db Noise Margin 7.6 db 15.1 db

Router Status
Account Name
Firmware Version	V5.01.16
ADSL Port
MAC Address	removed
IP Address	removed
Network Type	PPPoA
IP Subnet Mask	255.255.255.255
Gateway IP Address	removed
Domain Name Server	194.72.9.38 62.6.40.162
LAN Port
MAC Address	removed
IP Address	172.16.59.254
DHCP	On
IP Subnet Mask	255.255.255.0
Modem
ADSL Firmware Version	A2pB023b.d20e
Modem Status	Connected
DownStream Connection Speed	20463 kbps
UpStream Connection Speed	888 kbps
VPI	0
VCI	38

[stchedro]

I would guess at a) a port fault or b) extreem EM interference from a lift motor or transformer.

B) can only be detected with a spectrum analyser that is logging so you can try and correlate times with events. BT have a special team to sort this kind of thing out. Complain lots loudly!! And keep complaining until they fix it don't take no for an answer. Who is selling the connections? With this number it is corporate??

A) is difficult to diagnose but is a lot more frequent than BT admit to - most of the new gear is Huwaei which is close to total rubbish. But it is cheap.

Best of luck