LCP is down

For the last three weeks or so I have been getting this message in my routers logs.
It is unpredictable but happens usually every other day once or twice when the WAN uptime zeroes and starts again.

Since looking into this by running RouterStats I have discovered that although LCP is going down and reconnecting the modem is not losing sync and the connection speed is rock steady all the time as is the SNR even when LCP is lost. I have not seen this before, loss of connection but not line sync.
Line stats are:

Connection speed 4651 kbps 915 kbps
Line Attenuation 53.0 db 33.1 db
Noise Margin 7.1 db 6.2 db
Interleaving does not show as being on or off unless the line 'Channel: Fast ' means it is not set to on.

Router = Netgear DG834GT

The exchange (Blewbury) went to 21CN last month and I am pleased with the extra 0.5MB but not the now unreliable connection. Not that I am blaming the upgrade for the problems but it may be related. I get the discons whether the modem is set to G.DMT or ADSL2+ (G.992.5)

My ISP (Plusnet) say there is nothing wrong with my line and therefore they cannot do anything until I get several disconnections in one day. They are probaby right to say that as the line and SNR are stable but of course the connection is not.
I don't find that very satisfactory so what can I tell them to get this looked into more deeply.

You are on a longish line that resets from time to time. If when you are using the internet, you do not notice it, then ignore it.

To see Interleaving & ACL Mode (using Telnet) for Netgear DG834s follow: http://www.kitz.co.uk/routers/netgeardg834_interleav...

In reply to a post by XRaySpeX:

To see Interleaving & ACL Mode (using Telnet) for Netgear DG834s follow: http://www.kitz.co.uk/routers/netgeardg834_interleav...

Thanks for that. I already have that info in the DGTeam f/ware under Detailed driver information.
I now believe that interleaving is not active as I see Channel : Fast. What I don't know is would interleaving help my connection stability ?
It has dropped out twice today without losing sync and I have managed to get Plusnet to log it as a line fault now so I will wait for their ideas on what is going on.

Blewbury was one of the 'Race to Infinity' villages, is there no FTTC option for you, or even FTTP which is there in parts ?

In reply to a post by Zarjaz:

Blewbury was one of the 'Race to Infinity' villages, is there no FTTC option for you, or even FTTP which is there in parts ?

Yes it was me who got almost everyone in our village to sign up for the Race. But little good it did for us as BT would not upgrade our cabinet unless we gave them 45,000GBP !!

We do have a FTTC service here and some actually get 10MB due to the distance of the fibre cabinet we can connect to.
So that is why I am still on ADSL as its not worth upgrading for such a poor speed difference.

In reply to a post by jaba:

I now believe that interleaving is not active as I see Channel : Fast.

With Netgears 'Channel : Fast' does not refer to to the downstream; only the upstream. What you need to look at is the 'D:' (for depth) line in the normal detailed stats, if that's how DGTeam presents them.

Can anyone explain what might be causing my internet service to drop out with the corresponding message in the router log 'LCP is down' but my line is remaining stable with the modem synced and no noise spikes shown in RouterStats.?

In reply to a post by jaba:

Can anyone explain what might be causing my internet service to drop out with the corresponding message in the router log 'LCP is down' but my line is remaining stable with the modem synced and no noise spikes shown in RouterStats.?

I stand to be shot down by others.
LCP tends to be an authentication ISP issue and happens after exchange. Thus sync is not affected.
It is well documentation that many users get problems after 21cn exchange upgrades. Normally capacity is gradually increased over a couple of months, and is handled by OR.
Suggest you wait a couple of months and maybe ask ISP to check IP.
If still problems ask ISP if OR can reseat at exchange.
Maybe worth having SNR upped now to 9db temporarily.

ISP's Authentication Server, within ISP's network, is playing up. Nowt to do with your ADSL connection, therefore sync remains up.