Jane Dudman enumerates the key advantages of an optical network
"Although the networking industry has managed to squeeze bandwidths through copper far in excess of what was once thought to be its theoretical maximum, fibre undoubtedly has a higher theoretical maximum and is thus truly future-proof," says Matt Flowerday, chief executive of systems integrator Trescay Network Communications.
Leo Todd, marketing director of Colt Telecom, agrees. "There's a lot of pent-up demand for certain types of high-capacity services," he says. "There's a huge appetite for bandwidth from carriers building up their IP networks and corporates looking to hook up their data centres."
Optical networking is cost-effective networking, say the suppliers. 3Com, for instance, claims that while the average standard price for connections running over optical networks at anything between 155Mbps and 620Mbps could cost between $5,000-$15,000 per interface, optical multigigabit ethernet connections could cost under $200 per interface.
Dynamic provisioning, whereby optical channels can be split into many high-speed wavelengths, lets network managers turn up the capacity of their optical network at very short notice. Instead of having to wait for service providers to dig up roads and lay cable, users can get more bandwidth in days - hours, even - rather than weeks or months.
This facility, however, will depend on where the customer is based. Users in large cities will be best placed, as service providers and carriers start rolling out their high-capacity metropolitan area optical networks.
Blown fibre provides further flexibility for network managers who want to ensure they can install extra capacity at a relatively low cost. The plastic tubing for optical fibre is laid but with enough space to subsequently add fibre channels without further building work.
There are two ways in which optical networking is more secure than copper cabling. First, because it isn't an electromagnetic technology, fibre isn't affected by the electromagnetic fields of other kit, nor does it cause such interference. This is one of the reasons optical fibre is widely used in network backbones within buildings, where bandwidth demands are at their highest and where there is the greatest likelihood of electromagnetic interference from other building services, such as high-voltage power cables, which often run close by network cabling.
Second, while it is relatively easy to tap into copper cables and read the data running over them, it is difficult to do this with optical signals running over fibre. This makes optical networks more secure from hackers and industrial spies. Organisations that need secure networks, such as government and defence installations, already make extensive use of optical networks, sometimes right to the desktop.
The demand for bandwidth is growing but simply putting high-speed optical capacity across carriers' backbone networks won't solve corporate networking problems altogether. In fact, it will probably result in bottlenecks at the edge of those high-speed networks. "Once DSL is out in volume, it will drive huge amounts of networking capacity into data centres, but as well as long-distance capacity, local services will have to be delivered into local networks," points out Leo Todd, European marketing director of Colt Telecom.
This is something being tackled by network giant 3Com, whose Atrica spin-off is working on developing optical ethernet products, based on the familiar Lan protocol, but providing high-speed, end-to-end connections.
"Before this, there was ethernet at each end of a network connection, but packets had to be translated in the middle," says Adrian Hurel, 3Com's UK MD. With optical ethernet, no conversion is necessary. And since ethernet is so dominant in the Lan market, optical ethernet networking can be done cost-effectively, using existing ethernet chipsets, expertise and high-speed services. n
This was first published in February 2001