Sorry, but this is not how FTTC works. All the FTTC cabinets are connected to your local exchange, from the local exchange the connection goes to what is called a metro node, this metro node serves many exchanges.
I'm sorry but you are wrong. I know that for a fact. I know the routing of the fibre from the cabinets in my town for example, they don't go into my local exchange they go to one 4 miles away.
Where are you getting you information from may I ask?