Recent Linux Improvements that Impact TCP Throughput: Insights from R&E Networks

This paper reviews recent enhancements to the Linux kernel that impact network throughput, and their potential impact on Data Transfer Node (DTN) performance. In particular, we explore the benefits of MSG_ZEROCOPY and BIG TCP in controlled testbed environments at AmLight and ESnet. We compare performance on three different Linux kernel versions, on Intel vs AMD processors, and over multiple round trip times. Our results indicates that MSG_ZEROCOPY, in conjunction with packet pacing, provides up to 35% improvement in throughput, and that Linux 6.8 provides an increase in throughput of up to 38% on WAN and 30% on LAN compared to the 5.15 kernel. We conclude with recommendations for both host benchmarking and production-ready DTN configurations.