OTCP: SDN-Managed Congestion Control for Data Center Networks

TCP suffers from incast collapse in data center networks when used with partition aggregate workloads due to inadequate congestion control parameters. This causes poor application performance by under-utilizing the network, and can be one of the limiting factors in low-latency, high-throughput environments. To resolve this, we present Omniscient TCP (OTCP), a Software Defined Networking (SDN) approach to compute environment-specific congestion control parameters based on centrally available network properties. Through experimental evaluation in Mininet, we show up to 12x and 31x reduction in Flow Completion Time (FCT) at the mean and 95th percentile, an 8x FCT improvement on highly congested networks when combined with DCTCP [1], as well as improved fairness and reduced end-to-end latency.