A study of UDP and TCP FPGA implementation for data acquisition system

Two main protocol stacks for gigabit ethernet are currently widely adopted in the data acquisition system for high energy physics experiments. The first method is based on User Datagram Protocol (UDP), which transfer packets before an agreement is provided by the receiving party. However, the second method, called Transmission Control Protocol (TCP), establishes a connection through a process of the three-way handshake. We designed two FPGA projects, based on UDP and TCP respectively, on such a real application as ethernet communication module for ALICE calorimeters. The test of both projects is carried out on the same Xilinx Virtex-6 FPGA board, and data is captured through a professional network protocol analyzer. We analyzed the implementation methods and complexity, the variation patterns of data throughput, and the resource utilization of the two designs. The findings obtained under the same application scenario and test platform not only reveals the variation rule of actual data throughput, but also proved that the TCP would require twice as much FPGA resource for implementation as the UDP.