“…As networks become more complex, the probability of system failure increases, particularly for real-time WANs which contain hundreds of nodes. Examples of such safety-critical wide area networks include distributed battle management systems (Mosher, 1997), intelligent transportation systems (Andrisano et al, 2000), distributed health care networks (Yamamoto et al, 2000), global oil and gas exploration and research networks (MacIntyre, 1999), and aviation traffic monitoring systems (National Research Council, 1997;Cheng et al, 2000).…”