CWMP Connection failure

[#1]

I'm hoping someone more familiar with this error can reassure me that plusnet support are taking the correct approach.

I have a new broadband installation, but my connection is very unstable.  It connects for 5 mins, then fails and spends anywhere from 10-15 mins reconnecting.  Looking at the router event logs, I can see that every time the connection fails it is accompanied with a failure to access a CWMP server.

20:25:40, 09 Jan. (285893.460000) CWMP: session closed due to error: Could not resolve host
20:25:40, 09 Jan. (285893.440000) CWMP: Server URL: https://dbtpnhdm.bt.mo; Connecting as user: ACS username

Tech support suggest I have a problem with my local line and are proposing sending an engineer out to look at it, but I have my doubts about that approach because:

1) The last engineer who visited assured me that my line was fine all the way back to the exchange

2) If it were a local hardware problem surely the failure would be less predictable than to always fail with a specific server access?  That suggests to me a higher level problem.

My concern is that it's already been a week since the first attempt to connect me, and if we go through the process of sending an engineer out only for them to find no problems, then that's probably another week wasted.  Are my concerns justified or should I just shut up and let tech support do their jobs?

[#2]

See my post under 'Fibre Broadband - Increasing Line Profile Causing Router To Disconnect' my log shows similar to your problem

[#3]

The CWMP error is a symptom of the connection failure, not the cause. It means the router can't check in with Plusnet's management servers because the connection is down.

[#4]

OK, but why do I have to press Reset to get the hub to connect again? Something must be messed up that is causing a problem - is it that there is no broadband signal to connect to?

If this is so then the question is back to Plusnet, why do I have a break in the broadband signal - Plusnet say there is nothing wrong with my line!!

[#5]

That's interesting - so is there constant traffic between the router and the CWMP servers?  The reason I ask is that if this were an intermittent error caused by a local hardware problem, I'd expect to see a failure to access a variety of targets.  It seemed suspicious to me that the connection drop was always related to this one server. 

Or is it the case that the router only logs CWMP failures and there are actually others occurring which are going unnoticed?

[#6]

If the Plusnet automated line tests that tech support have run are showing a fault. Then it is likely that it's something that an Openreach engineer will need to deal with.
Not all Openreach guys have the same skillsets, so it may be that Plusnet have requested a different type of engineer depending on what fault their tests found.

[#7]

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@RubbishCat wrote:

That's interesting - so is there constant traffic between the router and the CWMP servers?  The reason I ask is that if this were an intermittent error caused by a local hardware problem, I'd expect to see a failure to access a variety of targets.

The traffic between your router and the CWMP server is far from constant. In fact it's very infrequent. There's always an attempt to communicate following a PPP disconnect/reconnect though i.e for each time your connection drops, there'll be a subsequent communication attempt when it comes back up.

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You won't see any other website connection request in the log because the router doesn't record that information. If it did, the on-board memory would soon fill up, as it's likely there'd be tens of thousands entries a day!

[#8]

Ah right - that makes perfect sense.  Thanks for the explanation!