TCP/IP Offload Engines by Davud Turkdil and Cory Ford

1. TCP/IP Offload Enginesby Davud Turkdil and Cory Ford Note that the relative CPU cost per megabit of throughput was higher for the faster CPU, in some cases more than double that observed at 800 MHz because memory and I/O speeds have increased at a much slower rate than CPU speeds. A TOE is a specialized network device that implements a significant portion of the TCP/IP protocol in hardware, thereby offloading TCP/IP processing from software running on a general-purpose CPU. All of the TCP/IP and checksums sections and much of the Interrupts, buffering and data movement can be taken over by TOE’s. Effectively relieving around half of the CPU overhead. TCP/IP processing can consume most of a CPU's processing power with standard Ethernet network interface cards. At small packet sizes, the CPU utilization can exceed 80%, significantly reducing the amount of CPU cycles available. System price/performance values for ASIC and discrete, board-level TOE solutions (AS OF 2002) Conclusion After a little research on the subject we have concluded that TOEs are very useful in saving CPU power and increasing throughput of the network. We believe once 10-GbE networks are more common then TOEs will be necessary. • Benefits • Reduces the bandwidth cost by 33% • Significantly increased CPU cycles for application processing • Significant drops in latency, reducing client response times • Direct Data Placement (DDP) • Inputting data directly into the application buffer • Greatly reduces TOE buffer size • Can currently achieve 3Gbps throughput