Below are the best settings I’ve been able to figure out for VDSL in Guernsey using a DrayTek router.
WAN >> General SetupWAN >> Internet AccessWAN >> Internet Access >> WAN1. Use your ISP given username and password. Sure suggests using MTU of 1500 and JT 1492, I couldn't see a differenceThis is also an interesting area because it gives some insight to what your line is capable of