Scalable 10Gbps TCP/IP Stack Architecture for Reconfigurable Hardware

TCP/IP is the predominant communication protocol in modern networks but also one of the most demanding. Consequently, TCP/IP offload is becoming increasingly popular with standard network interface cards. TCP/IP Offload Engines have also emerged for FPGAs, and are being offered by vendors such as Intilop, Fraunhofer HHI, PLDA and Dini Group. With the target application being high-frequency trading, these implementations focus on low latency and support a limited session count. However, many more applications beyond high-frequency trading can potentially be accelerated inside an FPGA once TCP with high session count is available inside the fabric. This way, a network-attached FPGA on ingress and egress to a CPU can accelerate functions such as encryption, compression, memcached and many others in addition to running the complete network stack. This paper introduces a novel architecture for a 10Gbps line-rate TCP/IP stack for FPGAs that can scale with the number of sessions and thereby addresses these new applications. We prototyped the design on a VC709 development board, demonstrating compatibility with existing network infrastructure, operating at full 10Gbps throughput full-duplex while supporting 10,000 sessions. Finally, the design has been described primarily using high-level synthesis, which accelerates development time and improves maintainability.