BT has admitted that it doesn't know exactly how it will implement its multi-billion pound upgrade of its national telecommunications infrastructure.
BT is planning to replace several existing circuit-based networks with a single IP-based one which it calls the 21st Century Network (21CN). The large scale project is expected to take around five years to complete and cost in the region of £10bn.
"We will learn as we go," said Clive Ansell, BT Group's strategy director, on Wednesday. "The potential economic gains are so high. We are a long way down the line in designing it, but designing it and building it are two different things."
Ansell, speaking at the 21st Century Communications World Forum in London, hinted that the look-before-you-leap policy was due to the pressure of dealing with cutting-edge technology, and the need for BT to keep costs down.
"What we need to do is switch some customers over, then figure it out for the rest of the country," said Ansell. "Everyone will have to move to these new technologies. The question is do we do it now, or in the next ten years… it's not an option to keep this old stuff going."
BT has said 21CN will bring significant saving to its operating costs, as well as enabling it to offer a greater range of services. But some in the City have expressed concerns, given that BT is the first telco to plan such a significant move into IP.
The BBC's Nick Ross was interviewing Ansell, along with Cisco's president of operations Robert Lloyd. Lloyd warned that the 21st Century Network project would involve a great deal of complexity.
"We've never run a public sector network," said Robert Lloyd, president of operations for Cisco. "But the comment that is consistent is that this is a transition from circuit-based networks to software-based ones. That inherently brings more complexity. But as we've built more networks for broadband customers, we are somewhere along the way in evolving [this]."
Ansell added that BT was looking for other telecoms players to also invest in a move to IP.
"Whether we actually do it depends on people in this room. There are operators who have to decide whether to spend money."
Paul Reynolds, chief executive of BT Wholesale, told the event on Monday that BT wants to destroy the telecoms sector's culture of closed proprietary systems in favour of the "plug-and-play" ways of the IT world. He also said that telecommunications equipment makers and software providers have given BT access to their source code, as a way of proving their kit was interoperable with that of other vendors.