If possible please change my DLM profile, from 'standard' to 'Fast'

Changing from the ‘Standard’ to ‘Fast’ DLM profile should allow for more errors on the line (whilst remaining in the ‘green’ error threshold, and potentially allow the DLM to remove any banding I have on my line.

The line itself never disconnects / resyncs, as far as I’m aware.

I have a couple of methods to reduce errors via the modem/router, if they accluminate at a much higher rate, during 24h.

My router downstream is syncing at 51806 kbps, but the ‘Max rate’ is currently estimated to be 63964 kbps.
So, perhaps the ‘Fast’ Profile would help to remove this banding / speed restriction on this line?

Good morning @cbdeakin. I am happy to look at changing the DLM policy (which is what you are referring to). The DLM profile I have very little control over. However, we must prove a good working line before we can do these things. If we request a DLM reset, and the DLM sees that there are too many errors, policing discards or other things then it will reject our attempt to override it - this is the main criteria for banded profiles, as you have alluded.

I have offered to send an engineer, and we would need to do this before we can action any of your requests, as we are unable to reset the DLM for the reasons I’ve mentioned above.

Hi Edd,

Thanks for your helpful reply.

Would the engineer be employed by Openreach, or Cuckoo?

Could we be charged for the visit, if any faults with our wiring / equipment are found?


@cbdeakin the engineer would be an Openreach engineer, Cuckoo do not employ engineers. We work with our colleagues at Openreach to provide different engineers for different types of issues.

You would only be charged if you missed the appointment or the engineer found the cause of any issues was caused by wilful neglect, ie you cut the line as an example. Since your line currently has a banded profile this would be something that is outside of your control.

I hope this clarifies your points.

Have a good evening,

Hi Edd, thanks for your response.

We installed a NTE5C faceplate years ago (we had a much older type previously), which improved the connection (particularly the phone line). I believe we disconnected the ring wire also, as this can improve performance.

That’s the main thing we were concerned about.

Is it correct that any connected telephone extensions may incur a charge? I think one is still connected.

Hello @cbdeakin, if your extensions are causing the problem then possibly (I’m not going to give you a definitive answer because until we’ve seen the report, we wouldn’t have the full facts). Have you got a faceplate (with two ports on) on your master socket instead of using the black micro filter we provide you? If so, then your extension wouldn’t be interfering with your broadband since the dual port faceplate [service specific faceplate] stops the broadband signal at the master socket.

Kind Regards

Hi, we installed a NTE5C + faceplate, which has separate VDSL and phone line ports.

If my VDSL modem reports a significantly higher ‘max rate’ than the current downstream rate, does this definitely indicate a problem? Or, is it just a rough estimate (maybe based on line attenuation?).

Can Cuckoo see any problems with the line via diagnostic / monitoring tools, or would this be managed by Openreach?

I’ve spoken with my dad, and he’s not interested in an engineer visit, at the moment :neutral_face:

I appreciate you taking the time to help.

Hi @cbdeakin :wave:

If your line is showing a max rate then this is likely to be achievable given satisfying conditions (this is much more accurate than an estimate using a checker, since the router/modem can take into account real time statistics).

We don’t monitor lines 24/7. However we have the ability to see most of the information we require and if we need some more then we ask Openreach to provide that information.

I can provide generalised advice about your line. However for engineer visits, the account holder would need to request and authorise acceptance of such visit. This is the reason why I’ve always asked for requests to be backed up via email from the account holder so we can help you in the proper manner.

Have a great weekend,

Hi, thanks for your help.

I can run the modem at an SNR margin of 2dB (with an Asus router / modem), which seems to be stable. This results in a downstream rate of 65357 kbps, with a ‘max rate’ of 79240 kbps. While downloading files this gives download rates of 62-65mbps, tested over a newly installed ethernet cable… This is really not a bad result, considering that I’m on an ECI cabinet, with likely over 500m between my property and the FTTC cabinet.

There’s another somewhat mysterious setting on my router called ’ UPBO - Upstream Power Back Off’, which is far as I can tell, seems beneficial if set to disabled. What’s interesting about this setting is, that it seems to force a higher SNR Margin on the upstream.

I don’t know if these settings would work well for other lines though, I expect the results are highly variable.

I’ll probably just run it like this, and hope it doesn’t disconnect or that the DLM doesn’t force the line to run at a lower speed. The CRC / error rate doesn’t seem that bad so far.

What I’ve observed so far, is that the stability of the line and error rates appears to depend on the SNR (Signal-to-noise ratio) of the various VDSL2 frequency bands, with the error rate increasing significantly if the SNR is below about 10db. According to this webpage, an SNR of 20dB or above, is considered excellent for stability. link here:

Hello @cbdeakin, I’d suggest if you are wanting to learn more and read about the way DSL based technologies work to have a look at www.kitz.co.uk which has some incredibly well written articles about the technology.

Kind Regards