sages that impact people the most. 5.9 INTERNET SIMULATOR Researchers at the Georgia Institute of Technology have created the fastest detailed computer simulations of computer networks ever constructed-sim- ulating networks containing more than 5 million network elements. This work will lead to improved speed, reliability, and security of future networks such as the Internet, according to Professor Richard Fujimoto, lead principal inves- tigator of the DARPA-funded project (Defense Advanced Research Projects Agency). These "packet-level simulations" model individual data packets as they travel through a computer network. Downloading a Web page to an individ- ual's home computer or sending an e-mail message typically involves trans- mitting several packets through the Internet. Packet-level simulations provide a detailed, accurate representation of network behavior (e.g., congestion) but are very time consuming to complete. Engineers and scientists routinely use such simulations to design and analyze new networks and to understand phenomena such as Denial of Service attacks that have plagued the Internet in recent years. Because of the time required to complete the simulation computations, most studies today are limited to modeling a few hundred network components such as routers, servers, and end-user computers. "The end goal of research on network modeling and simulation is to create a more reliable and higher-performance Internet," says Fujimoto. "Our team has created a computer simulation that is two to three orders of magnitude faster than simulators commonly used by networking researchers today. This finding offers new capabilities for engineers and scientists to study large-scale computer networks in the laboratory to find solutions to Internet and network problems that were not possible before." The Georgia Tech researchers have demonstrated the ability to simulate network traffic from over 1 million Web browsers in near real time. This feat THE INTERNET RULES-IP TECHNOLOGIES means that the simulators coul