Dynamic Adaptive Marking Strategy Based on DCTCP in Data Center Networks

The Incast problem is common in data center networks (DCNs), which is easy to make throughput collapse. Today’s TCP/ECN protocol, such as Data Center TCP (DCTCP), uses Explicit Congestion Notification (ECN) to send feedback to the sender to achieve high throughput and low latency. But as the number of senders increases further, DCTCP can not suppress incast effectively. The ECN-based mechanism is static marking, which does not guarantee high throughput and fairness at the same time. In addition, the mark-tail strategy in DCTCP causes congestion signals to experience longer queuing delays, resulting in queue oscillations. In order to overcome these shortcomings, this paper proposes a dynamic adaptive(DA) marking strategy, named DCTCP-DA, which automatically adjusts the marking strategy according to the queue gradient. This scheme can guarantee the fairness of different flows. When encountering burst traffic, it can send the congestion signal to the sender faster and prevent the occurrence of timeout. Simulation on NS-3 shows that DCTCP-DA can delay the throughput collapse caused by Incast, control the queue more effectively, and improve the fairness of different flows.