Improving and Evaluating TRex Traffic Generator through P4 Switches

Sammanfattning: Traffic generators, as an indispensable tool to test devices under test and networking protocols, help researchers to execute performance inspection and optimization. Among all traffic generators, TRex is an open-source, high-performance, and low-cost traffic generator which is built on Data Plane Development Kit (DPDK). It supports stateless traffic generation patterns and the modification of fields and length for each packet. More importantly, it can emulate realistic TCP stateful traffic. Although DPDK can greatly improve the packet processing speed, the maximum throughput of the system is limited by the bandwidth of network interface cards (NICs). This thesis combines TRex traffic generator and a P4 programmable switch to construct a high-speed, feature-rich, and cost-effective traffic generation system. Our basic idea is to ”shift” the bottleneck of NICs’ bandwidth to a P4 programmable switch. In particular, TRex only generates small packet headers while the payloads of the packets are generated on the P4 programmable switch by fast recirculations. Since sending small packets consumes less bandwidth, TRex can reach a higher packet rate. Thanks to the enormous bandwidth provided by the programmable switches and the higher packet rate, our design can generate traffic beyond the bandwidth of the NICs. Besides, we build upon the original TRex and completely inherit its toolchain, which exhibits high transparency. That is to say, the users do not need to modify the profiles that generate traffic to use our system. We establish and test our design on Virtual Machines, and then perform a real-world performance evaluation on a physical server with 2×100Gbps Mellanox NICs. The evaluation results show that our system can achieve more than 2x throughput for Advanced Stateful mode than the TRex without any modification when the average packet size reaches 1367 bytes.