MAKING NETWORK INTERFACES LESS PERIPHERAL

A barrier to delivering improvements in network bandwidth and latency to users is the network interface (NI), which connects a network to th e host computer that runs the network software. An NI includes hardwar e that exposes an internal interface-such as device registers-to a hos t processor. A key problem with most current NIs is that their interna l interface is similar to that of a disk's interface. Because of such limitations, current NIs will not be adequate for use with newer, high -performance networks and host computers. High-performance local area networks have advanced so far that some view them as a new class of ne tworks called system area networks (SANs). Emerging SANs deliver bandw idths of 10 Gbps or more and latencies of tens of nanoseconds-two to f our orders of magnitude better than that delivered by most current LAN s. New hosts demand much higher performance. If NIs do not adapt to th ese changes they will become a barrier to improving network performanc e. To solve this problem, future NIs should appear to their hosts more like memory than like disk interfaces. The authors argue that treatin g NI accesses like memory accesses is justified by the importance of n etwork performance to future computers.