Good news for those with stable Openreach FTTC lines which could see small increases in their sync speeds next year.
The current default target SNRM is 6dB but with effect from March 2017, the NGA DLM (Dynamic Line Management) may select 3, 4, 5 or 6dB depending upon how stable the line is.
We had been monitoring the Openreach trial of a 3dB Target SNRM on our forum
which was undertaken in April earlier this year. Those users who were on the trial saw their speeds increase and on the whole the trial appeared to be sucessful.
Based on our observations speed increases are roughly in line with the following figures.~ For existing Sync speeds of around 20Mbps - each 3dB is worth 3Mbps
~ For existing Sync speeds of around 40Mbps - each 3dB is worth 6Mbps
~ For existing Sync speeds of 60Mbps or more - each 3dB is worth 11Mbps.
BT wholesale ADSL (copper) lines already have a 3dB profile available to them. Obviously this increase wont make any difference if you are already syncing at the maximum speed ie 80Mbps or 40Mbps if you are on a 40/10 or 40/2 product.
For more information on BT's DLM see What is Target SNR MarginBT DLM system BT DLM process
Credit to ejs
for spotting the change in SIN 498
published Nov 2016