High-Speed, Short-Latency Multipath Ethernet for Data Center Area Communications

In this paper, we propose a simplified multi-path aggregation scheme, Ethernet with flow label for multi-path, called EFL-MP. There are several aggregation schemes, such as link aggregation and multi-path TCP, for multi-path load balancing. However, link aggregation does not distribute a single flow into multiple paths due to its MAC address based flow dispatch. In addition, the multipath TCP scheme is not suitable for implementing into hardware because of the implementation complexity caused by the management of the two stages of sequence number (SEQ) (i.e., the SEQ assigned to a path and the SEQ assigned to the flow); thus it fails to provide high throughput and short latency. To maximize data transfer throughput and minimize latency, we employed a single-stage sequence number scheme with a reorder-buffer-usage-based retransmission activating algorithm. Simulation results show that EFL-MP provides high throughput and short latency despite its simple scheme, and its throughput and its latency suit to use for interconnection transport. In addition, we demonstrate that our proposed retransmission activating algorithm activates retransmission due to packet losses earlier than the conventional timer-based retransmission activating algorithm.