SMOOTHIE: Efficient and Flexible Load-Balancing in Data Center

In the context of contemporary data center networks (DCNs), optimizing resource utilization and preventing congestion are critical objectives. This paper introduces SMOOTHIE, a dynamic path load balancer specifically designed for real-time congestion management using Inband Network Telemetry (INT) for collecting network state pieces of information and Segment Routing Version 6 (SRv6) for rerouting traffic. Leveraging the programmable nature of the P4 programming language, SMOOTHIE effectively achieves its goals. Our experimental results showcase SMOOTHIE's superiority over conventional Equal-Cost Multipath (ECMP) routing and its competitive performance compared to other congestion-aware load balancing solutions. We assert that these findings can be attributed to SMOOTHIE's proactive congestion response, which minimizes the necessity for TCP congestion window resizing, and its ability to intelligently reroute flows onto optimal paths, thereby substantially reducing route flapping. These outcomes highlight SMOOTHIE's potential to significantly enhance network performance within DCNs. Furthermore, SMOOTHIE offers enhanced manageability, ease of maintenance, and simplified deployment through a centralized controller, further underscoring its value.