BT is to start moving it's £10bn 21st Century Network (21CN) onto the next stage with trialling mass migrations of customers.

Currently two small South Wales towns, Wick and Bledinog have been used as BT's test bed to prove the technology before further rollout in Swansea and then to the rest of the country.
BT hopes that the move to the IP network will be seamless with customers not noticing the change, with downtimes in the region of minutes or even seconds during the night.

The telco says it has proved the technology behind its £10bn nationwide 21CN project in two g. Now it has to demonstrate that it can move people over to wholly IP-based voice and broadband exchanges without them noticing.

BT has said it has spent "tens of millions" on the trials, but refused to comment on whether the savings of 21CN will be passed onto customers.