Line noise, replaced NTE & Filter, Sync lowered

I just had (another) incident of a noisy line. Last time the engineer fixed it by replacing the NTE.

It turned out to be the NTE again (lightning maybe?), but this time the engineer replaced the filter as well. Didn't think much of it until after he'd left.

Checked my stats, and I've lost 6MB/s in downstream sync speed.

He's fitted a MK3 filter, and left with my MK2 filter (that I purchased!).

Is this the likely cause of the sync speed dropping? Or maybe a dodgy NTE replacement?

Or could just be DLM reacting.

You can bypass the MK2 or MK3 and still use the test socket to show if filter is dodgy i.e. http://www.coolwebhome.co.uk/faceplate/

Hi Andrew,

DLM had kicked in already, and banded me to 74MB/s, but the Fritzbox shows the attainable rate as well.

Prior to the visit this was ~80MB/s, even though the line was connecting at 74MB/s. (I was waiting for DLM to back off).

I presume that the attainable rate is what sync could be achieved, if DLM was disabled?

Receive Direction Send Direction
Max. DSLAM throughput kbit/s 74000 20000 <-- DLM banded, was 80MB/s
Min. DSLAM throughput kbit/s 128 128
Attainable data rate kbit/s 74626 21115 <-- Attainable fluctuates, was >80MB/s
Current throughput kbit/s 73999 17382 <-- DLM restricted, interleaving (8ms) on upstream

Edited by AndyPandy (Wed 08-Jul-15 10:32:16)

On attainable - basically right though it may not happen if error count goes up as you push to that limit

Also a small chance someone just went live with an adjacent pair in the copper bundle and cross talk has hit you, massive coincidence but possible.

I had the same result when the faceplate filter was replaced with a Mark 3 type. I waited for 3 weeks but the speed and latency never recovered. I replaced the Mark 3 with a Mark 2 faceplate and my speed increased to that previously and latency dropped by 8 ms.

Thanks for the replies both, looks like I'll be trying to source another MK2 filter.

I've already been hit by crosstalk, but it's never been as big a jump as that before. I started on 93MB/s attainable, which has eroded down to just over 80MB/s (before all this).

According to the engineer my line length is 336 metres. Roll on vectoring!

Edited by AndyPandy (Wed 08-Jul-15 11:42:27)