FTTC, fibre to the cab and copper/alu to the premises
FTTP, fibre to the premises
Infinity has limit of approx 1.4km from cabinet, will still work at greater length, but with reduced speed. Line checker however may not let you order it if line length exceeds that stated above.
If fed direct from exch (no cabinet)Infinity is not curently available
Broadband also won’t work if fed by cable with loading coil or DACS present and no obligation to remove them au gratis. The latter does have an exemption figure of I believe about 8 grand, but if anything over that due to line rearrangement its either cough up the surplus or don’t have it
Interference or REIN has a myriad of causes, electric fences, strip lights, lifts, alarms etc etc. Check for yourself by tuning in a radio to 612khz AM/MW and you should hear noise if REIN is present.