The network is the test bed

Scientists often need to correlate massive amounts of data located at different sites, and today's networks are beginning to accommodate this need. One example is the OptIPuter project (www.optiputer.net), a collaborative research project of the University of California San Diego (UCSD), the University of Illinois Chicago (UIC), and others that was built to show that today's technology can handle the task.

The backbone of the OptIPuter is a 10-Gbps optical network that can dynamically allocate bandwidth as needed, which lets the OptIPuter put unused resources to work handling data-intensive applications such as life science, earth science, microscopy, and imaging. Because network engineers at participating sites are free to expand or reconfigure their network nodes (each site, or "cluster," may contain several hundred nodes), the testing of the network never stops.

Computing and network researchers have developed custom software that automatically assigns bandwidth where needed. Part of the bandwidth allocation comes at the physical layer, where optical switches from Glimmerglass and Calient let engineers reconfigure the network to accommodate changing bandwidth demands.

"Because it's a research project, the network is in fact a test bed," said OptIPuter chief infrastructure officer Greg Hidley at UCSD. "Every time someone reconfigures or adds to the network, we have to test that it can still allocate bandwidth as needed." Testing involves measuring the throughput at the application layer with network software, but Hidley and others can also perform lower-layer tests such as packet monitoring and optical power measurements.