There is no "settling period" of the 10-day kind that BT Wholesale and many ISPs still say.
Note that the line-configuring DLM is by Openreach, and controls all FTTC circuits. Not the BT Wholesale DLM that only controls non-LLU ADSLx lines. However on BT Wholesale connections the sync speed is passed from Openreach to the BTW one which sets the IP Profile for those.
On a migration the Openreach DLM is reset to the stability settings requested by the ISP and interleaving is turned on. The effect of turning on interleaving, if previously on Fast Path, is that latency/ping is increased by 8ms and the sync speed will be lowered by several Mbps.
Those two things will normally return to normal within 2-3 days and the sync increase.
Do not try re-sync'ing to improve the speed during the rest of the first day or the whole of the second day. The OR DLM is particularly sensitive then. In effect, a 2-day period.
My broadband basic info/help site - www.robertos.me.uk.
Domains, site and mail hosting - Tsohost
Connection - Three 4G, tbb tests normally 35-45Mpbs down, 65Mbps off-peak, 9-24 up.
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Edited by RobertoS (Tue 31-Mar-20 11:37:22)