Attainable speed lower than VDSL Range B (Impacted) low

I've been dealing with another slow internet connection and it's on BT Infinity this time.

The house must be very close to the cabinet as the speed estimates for VDSL Range A are 80 down and 20 up for low as well as high. VDSL Range B is 80/20 high and 63.5/18.3 low.

The line comes into a BT 201D junction box in the basement with an NTE5 master socket connected next to it. There's only one telephone line active. The router is two floors above in the study - on another master socket. Cabling from the 201D to internal phone sockets around the house is Cat5e. There are lots of things plugged into phone sockets without microfilters (burglar alarm, Sky Box etc).

Initially, I was getting attainable of 35449/13088 with a sync of 35449/9998 from the study. From the basement master test socket this improved to attainable of 54572/22808 and actual of 54572/9998.

Putting a Mk3 interstitial filter in to the basement master socket, disconnecting the ring wire and replacing the study master socket with a secondary as a data extension has given a significant speed boost from the original. There's now no significant difference between attainable speeds either from the study socket or the basement master test socket. It's a 54% improvement in downstream attainable and a 74% improvement up.

There's nothing more that can be done with internal wiring but it's still well short of the low speed estimate for an impacted service. The upstream attainable is excellent at 22808. I'd expect downstream attainable to be a bit better than 54572.

There's no noise on a quiet line test.

With the BT Home Hub 5 back online, the IP Profile is 50.9 and downstream speedtest is about 48Mbps - a fifty percent improvement on the 32MBps I first measured.

I know the fact the upstream sync of 9998 tells me it's on BT Infinity 1 but we're not even syncing at 55Mbps with the Home Hub.

Ideally, I'd like to sort the problem out so that an 80/20 service can be used.

What's the best way to get BT to deal with this? Will BT deal with this?

All suggestions gratefully received.

What's the attenuation?

Very good question, I'll answer that when I've been back and had another look.

Hang on, max sync on Infinity 1 is 55000/10000.

In reply to a post by caffn8me:

actual of 54572/9998.

What are you hoping for?

Oh I see, you want Infinity 2

the IP Profile is 50.9

What is the upstream IP Profile? 10 or 20?

Something isn't right with the line if the attainable isn't well over 80 with those sort of estimations

Max sync, yes, but I've posted attainable figures. I believe these should show what the line is capable of regardless of the IP profile in use. Look at the upstream. Line sync restricted to 9998 but attainable is 22808.

We're not achieving the maximum downstream sync on the HH5. The Draytek I used for testing fares better.

Precisely.

I assume you have checked the sync from the test socket in the basement NTE5 since your cleaning up of the wiring?

The 50.9 IP Profile doesn't suggest to me (on a reverse calculation) a likely banded line profile, but the figures from the HH5 stats page when connected to the test socket would be useful.

Yes - as previously stated, there is no difference between a connection direct to the basement test socket and the study secondary now.

It's going to be the end of this week before I can go back again so further stats will have to wait.