ATLANTA, GA -- One of the star attractions of the Supercomm trade show, starting here today, is likely to be a demonstration of software scalability being staged at booth 2717 by Sycamore Networks Inc. http://www.sycamorenet.com.

The demo comprises two walls of PCs, emulating the equivalent of 100 Sycamore SN 16000 optical switches linked together in what amounts to a working optical network that's far bigger than any that exist in real life right now. Visitors can see, via management systems, how the software handles tasks such as automatic provisioning of end-to-end connections and automatic rerouting of those connections around network failures.

The point that Sycamore is making is that software scalability is a huge issue for carriers - and it thinks it's found a way of addressing that issue that goes way beyond its demo at Supercomm.

Here's the score. Up to now, the big focus on optical switch developments has been on hardware scalability - how many fibers, wavelengths, and circuits the switches can handle. However, it's one thing to develop a big switch and quite another to develop software that can make large numbers of those switches work together seamlessly in a network - particularly as the software must be incredibly reliable. The slightest glitch could spell disaster for a carrier, because the switches carry enormous amounts of traffic.

Service providers are very sensitive to this issue, having witnessed what happened with frame relay services in the mid 90s. When demand for frame relay took off, carriers built bigger and bigger networks and then suffered some catastrophic blackouts. In each case, the root cause turned out to be that the switch software hadn't been designed for very large networks, according to Amy Copley, Sycamore's product marketing manager.

The problem is that it's hard for vendors to prove to carriers that their software has been designed to scale and will be extremely reliable in practice. It isn't feasible for them to build a real, large-scale network in a lab - so Sycamore is doing the next best thing and emulating such a network using PCs. In other words, the demo on its booth isn't a "one-off project" for Supercomm. It's being used within Sycamore to test its software developments.

The big question is whether Sycamore's emulated network is a true likeness of a real one. Sycamore points out that its switch network operating system - now named Broadleaf - runs on Linux. As the PCs in its demo are also running Linux, the Broadleaf software in them is identical to the one used in the vendor's real-life switches.

- by Peter Heywood, International Editor, Light Reading, http://www.lightreading.com