Router fault has caused DLM to reduce line speed by 50%. How can I get this reset quickly?

[Tiyuri]

So last night a new firmware version was pushed to my router, which ultimately bricked the router. After trying to resolve the issue with the router for a couple of hours (A deep dive into tftp, 30/30/30 resets, etc) I decided to give up and purchased a new router/modem.

With the new router everything is working as it should. But the line speed has dropped drastically. After some troubleshooting I think I've ruled everything out aside from DLM. I've had similar issues in the past where a router fault caused DLM to detect dropouts and reduce line speed.

Now that everything is up and running again. What's the best way for me to request a DLM reset given current circumstances? Online chat isn't available and I'm unsure whether phone support will be able to help me.

Any recommendations would be great!

Thank you

[imjolly]

the router should recover speed in a few weeks if the connection remains stable

[Tiyuri]

A few weeks is quite a long time! Particularly given that I'm working from home right now due to Covid. I know engineers are able to perform a DLM reset but it seems it might be possible remotely? I'm wondering who might be best to contact.

[licquorice]

Engineers can't perform a reset themselves, they can only request one, and then only after having cleared a line fault.

[Tiyuri]

A few years ago I had a similar issue with a router causing DLM to kick in. I had an engineer in the property, explained the issue to them, and right then and there they requested the DLM reset and I had my speed instantly restored... 

Is this still my only option? I'm assuming getting an engineer visit is very difficult right now

[licquorice]

If you line hasn't been banded, it shouldn't take too long for DLM  to relent. You can tell if you have been banded as your speed will be at a round figure rather than some random speed.

[Tiyuri]

Sadly it's been almost exactly halved. It's hard capped at 25mbit on a bt infinity 2 plan. 

[licquorice]

But is it exactly 25.0 or a random figure? I don't think 25M is a band profile in any case, it would be either 20.0 or 27.4

[Tiyuri]

My router conducting a speed test (via speedtest.net / google) is reporting precisely 25mbit down and 1mbit up. These don't match the line speeds reported by the router, which are below:

Quick edit:

I know the noise values here aren't ideal. But I've been getting 50mbit for years with zero issues. The only thing that's changed is the router bricking and causing a ton of disconnects on trying to fix its firmware. Also this is a new router obviously, but I can't see any reason why it would reduce bandwidth by 50%. It's an Archer VR2800 if anyone has any ideas there.

[licquorice]

Of course not, download speed will always be lower than sync speed due to protocol overheads. Looking at your stats, you have a 3dB noise margin, therefore DLM is perfectly happy with your line and hasn't reduced your speed. you are getting your maximum speed possible.