BT's 21st Century Network

BT plans to replace the old phone network - used for almost 100 years - with a broadband-based connection - a 21st Century Network

Up to £10bn is being spent over five years, and eventually every exchange in the UK will be updated.

The eventual plan is to move all BT subscribers from the traditional PSTN (public switched telephone network) to a new IP (internet protocol) network.

Via BBC