Fairness Improvement of Different TCP Congestion Control Algorithms Using P4 Programmable Data Plane

A wide variety of congestion control algorithms have been developed for the transport protocol of TCP/IP. A related study revealed that the communication performance becomes unfair depending on the buffer length of switches or routers in the end-to-end path when communication flows using CUBIC TCP and Bottleneck Bandwidth and Round-trip propagation time (BBR) compete with each other. Therefore, we propose the fairness improvement method between different types of congestion control in the programmable network by using P4 programming. The proposed method provides multiple queues to each congestion control in the switches or the routers for relaying. The proposed method then assigns incoming TCP flows to those queues for each congestion control algorithm. The congestion control algorithm is determined by P4, which implements a programmable data plane. Three types of packet scheduling are used to ensure fairness when sending packets. We evaluate the effectiveness of the proposed method using the network emulator “mininet” and the communication performance when the queue length of the relaying switch.