Of course, simply having the system is not enough. It has to be used. "For years, we struggled to get the doctors to use the system," Beer said. "In 1998, I surveyed the doctors here and found that one-third were willing to computerize. Another third said they'd wait for it to go away, and the last third said they'd never do it and we'd have to wait for them to retire." But in 2000, computer use became a condition of employment, he noted.

The data offered by CPRS has evolved over the years as the network's capacity and use have grown, said Dr. Robert Kolodner, chief informatics officer at the VA. Initially, it offered only summaries of specified portions of a patient's medical file, later evolving to full medical charts. Images were added for same-facility users in the late 1990s, but as of September 2005, any doctor in the system can call up the X-rays, MRIs or other data of any patient, he said.

September saw another service milestone when the records for New Orleans veterans were online again less than 100 hours after Hurricane Katrina wrecked the VA facilities in the city. Local personnel were able to rescue the Vista backup tapes and get them to Houston to load them onto the servers there, said Dave Bradley, a VA technical adviser in Coatesville, Pa.

As for the network behind that data, it's been evolving for two decades, Bradley said. Having advanced from 9.6Kbit/sec. connections in the 1980s, to 1.54Mbit/sec. T1 connections in the mid-1990s, to managed 45Mbit/sec. Digital Signal Level 3 connections in the late 1990s, the VA system now has an Asynchronous Transfer Mode-based network, he noted. There are ATM switches at four data centers in Reston, Va.; Dallas; Kansas City, Mo.; and Sacramento, Calif. These connect to 19 regional networks, which support various numbers of medical centers. Clinics that are satellites of a medical center connect to the network through that medical center. Plus, there is a data storage center in Austin.

The backbone nodes usually use 20Mbit/sec. connections, with the medical centers connected to the backbone via 4Mbit/sec. to 10Mbit/sec. connections, Bradley said. Connections out to the clinics depend on local engineering decisions and often involve T1 lines, he said. All the circuits are arranged through standard federal government contracts, with Sprint as the primary vendor, he added.