To be totally accurate it is the length of the line from your premises to the PCP (the original cabinet) plus the distance from the PCP to the FTTC CAB as it at this point that the line is connected to the DSLAM which terminates the fibre.
The two cabinets can be up to 50 metres or so apart.
Ex <n>ildram , been to SKY MAX - 15,225 Download
BE Unlimited - 21,000 Download 1,200 Upload ON THE LINE THAT SKY COULD ONLY PROVIDE 15,255 DOWN AND 800 UP ON!!!,
Moved house, now BE Unlimited 6,500 Down, 1Mb/s up - gutted!
FTTC Cab installation commenced 12th April - expect full 80 / 20 - bye bye BE, hello BT Infinity soon!