Andre

There will already be fibre cables from Banbury to Brackley, so that is the existing Backhaul for Brackley, If your cabinet is on the route between the two Openreach will splice a fibre from your Cabinet into the cable at the nearest Manhole. If your cabinet is 'beyond' the exchange manhole the fibres will be pulled / (blown if only a single cabinet) down (existing) duct to those cabinets. (Note blowing is only possible for small cables, 4 fibres, and short distances, so most of this will be pulled, FTTP could be blown to the house from the last splitter).

If there is an existing cable route out the other side of the exchange, say to Buckingham, Cabinets will be spliced into that cable to pick up fibres back through Brackley to Banbury

Imagine 3/4 of a spiders web hanging by a thread down the missing quadrant. Ypur cabinet is either connected to the hanging thread or the end of one one the radial threads.

They will only put a new cable in between Banbury and Brackley if all the existing fibres are used. I suspect that if this was the case Brackley would be later in the rollout!

The ability to use existing infrastructure is likely to have a big impact on where places sit in the rollout. So child sites are likely to have enough spare fibres existing to the parent to cater for all the cabs that are planned to be connected up. This would reduce the cost/manpower/capital needed to a cost in point.

Thanks Kitkat but that still doesn't quite answer my question

I would have thought that the ducting in a town was topologically a star (although some branches might be trees) and that therefore all the fibres from all the cabinets would eventually meet at a single point - the exchange. In your reply you state that cabinets on the other side of Brackley might be spliced into the Buckingham cable. That suggests something more akin to a bus or else that new ducting will be run from those cabinets to the main ducting for the backhaul.

http://en.wikipedia.org/wiki/Network_topology