The first stage of a project to build one of the world's most advanced telephone networks has been completed.
The so-called 21st century network (21CN) is being built in the UK using Internet Protocol technology.
The massive upgrade, the first of its kind, will cost British Telecom £10bn and take until 2010 to complete.
It will open the way to new services as well as making existing services quicker and cheaper than before.
1,500 man years
The first person to use the new network was schoolgirl Laura Wess from South Wales.