N Reality..l！(As2015) 国家重点实验室 App App App 1 n App1 App2 App n Operating System Operating System Specialized Packet Specialized Packet Forwarding Hardware Forwarding Hardware Closed equipment Operating a network is expensive Software bundled with hardware. More than half the cost of a network Vendor-specific interfaces. Yet,operator error causes most Over specified(过度制定规范) outages. Slow protocol standardization. Few people can innovate Equipment vendors write the Buggy software in the equipment code. Routers with 20+million lines of code Long delays to introduce new 。 Cascading(连续不断的)failures, features. vulnerabilities(弱点)，etc,Reality…!!!! (As 2015) Operating System App1 App2 App n Specialized Packet Forwarding Hardware Specialized Packet Forwarding Hardware Operating System Closed equipment • Software bundled with hardware. • Vendor-specific interfaces. Over specified (过度制定规范) • Slow protocol standardization. Few people can innovate • Equipment vendors write the code. • Long delays to introduce new features. Operating a network is expensive • More than half the cost of a network. • Yet, operator error causes most outages. App 1 App 2 App n Buggy software in the equipment • Routers with 20+ million lines of code • Cascading （连续不断的）failures, vulnerabilities（弱点）, etc