The emergence of fast, cheap embedded processors presents the opportunity for processing to
occur on the network adapter. We are investigating how a system design incorporating such an intelligent network adapter can be used for applications that benefit from being tightly integrated with the network subsystem. We are developing a safe, extensible operating system, called SPINE, which enables applications to compute directly on the network adapter. We demonstrate the feasibility of our approach with two applications: a video client and an Internet Protocol router. As a result of our system structure, image data is transferred only once over the I/O bus and places no load on the host CPU to display video at aggregate rates exceeding 100 Mbps. Similarly, the IP router can forward roughly 10,000 packets per second on each network adapter, while placing no load on the host CPU. Based on our experiences, we describe three hardware features useful for improving performance. Finally, we conclude that offloading work to the network adapter can make sense, even using current embedded processor technology.
