The trial network, linking BT exchanges in central London, Woolwich and Cambridge, has carried over 160 million calls and provided valuable testing and learning that is now being deployed with live customers.

As BT gears up to migrate some 350,000 customers in Cardiff and the surrounding area onto 21CN over the course of this year, the completion of the trial sends a further signal that 21CN has entered a new phase, with BT focusing on the mass implementation of the new network.

The start of the 21CN voice trial in 2005 marked the beginning of BT’s muti-billion pound investment in a national next generation network for the UK. The trial formed a critical part of BT’s 21CN testing plans to ensure that customers continue to enjoy the high standards of service quality on 21CN as they do today on the existing PSTN network, and has been instrumental in shaping BT’s plans for implementing 21CN across the country, and the rest of the globe.

Matt Beal, CTO of BT Wholesale said, “By the end of this year, we will have upgraded 350,000 lines. And in other parts of the country, we’re busy preparing exchanges and upgrading infrastructure to enable national migration from early 2008, starting with broadband.”