One of the first fully-functional voice over IP (VoIP) networks goes online next week after project managers overcame an installation nightmare and a once in a millennium deadline.

The £5m Millennium Dome network, which is one of the first to carry VoIP on the Lan, will play a critical communication role in the months following 1 January keeping ticketing and administration staff in touch.

While over 12 million people are expected to visit the site, installation of the leading edge technology across more than 80,000 square feet using 90km of cabling wasn't easy.

Haroon Khawaja, network consultant at network services company Workplace Technologies, which carried out the project, said that problems first arose after the fibre for the data was laid in polluted ground and then buried under concrete. When a copper phone network was then requested, engineers vetoed digging up the concrete because of the possible toxic leaks.

A wireless workaround solution was considered but this interfered too much with radio microphones to be used during the millennium show. It was also hampered by the dome's unique design. Using the existing fibre for voice became the only solution.

Workplace installed a 3Com Lan telephony switch on the ATM-based network with trunks to a Lucent PBX. In total there will be around 64 IP phones which will be situated at locations ranging from admin kiosks to 40 metres up gantries.

Frank Barber of the New Millennium Experience Company, and the Dome's IT infrastructure architect, said: "VoIP is more complex to set up technically and the technology is not fully anglicised yet. For example, on the interface to PBX some European standards are not supported."