Analysis: IP, IP, hooray... fibre's on the way

Some day the world will be connected by fibre with virtually unlimited bandwidth – but most of us are going to be stuck with copper for a long time.

Today only very large organisations have all-fibre links to core optical networks.

For the rest of us, next-generation networks will remain a hybrid of the old and new: DSL data piggy-backing old steam voice lines; or cable broadband running over fibre to street cabinets, and then on coax into homes and offices.

But much is changing at the carrier level. Stuffy old British Telecom is leading the world with its 21st Century Network project, which aims to transform its entire infrastructure to packet-switching, using the Internet Protocol like the web.

Not only does this make more efficient use of lines, but a single homogenous system avoids bottlenecks at gateways between the multiple technologies currently in use.

Networking and communications experts at last week’s Netevents forum in Evian, France, viewed this exercise with a mix of admiration that BT was doing it at all, and scepticism that the company would manage to go all-IP. One told me: “The standards are not in place, so BT will have to create its own.”

He said BT is big enough to take the world with it, when others start following its lead. But of course the world could also wait to learn from BT’s mistakes and go a different way.

A big market at the moment is in “midband” links connecting a fixed set of sites, such as dispersed company premises, at between 2Mbit/sec and 45Mbit/sec, using leased lines connected to optical metropolitan networks.

These links can be end-to-end Ethernet, so connected sites are essentially sitting on the same local network.

For capacities above 20Mbit/sec it is economical to install new fibre to premises; below that the game is to cram more data down the copper, according t o Gary Bolton, vice-president of product marketing at Hatteras Networks.

His company produces boxes that allow a two-wire E1 leased line rated at 2Mbits/sec to provide a two-way link with a capacity of up to 5.7Mbits/sec. Higher capacities are achieved by aggregating more wire pairs.