RepNet : Cutting Latency with Flow Replication in Data Center Networks

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

6 Scopus Citations
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  • Shuhao Liu
  • Wei Bai
  • Kai Chen
  • Zhiping Cai

Related Research Unit(s)


Original languageEnglish
Journal / PublicationIEEE Transactions on Services Computing
Online published15 Jan 2018
Publication statusOnline published - 15 Jan 2018


Data center networks need to provide low latency, especially at the tail, as demanded by many interactive applications. To improve tail latency, existing approaches require modifications to switch hardware and/or end-host operating systems, making them difficult to be deployed. We present the design, implementation, and evaluation of RepNet, an application layer transport that can be deployed today. RepNet exploits the fact that only a few paths among many are congested at any moment in the network, and applies simple flow replication to mice flows to opportunistically use the less congested path. RepNet has two designs for flow replication: (1) RepSYN, which only replicates SYN packets and uses the first connection that finishes TCP handshaking for data transmission, and (2) RepFlow which replicates the entire mice flow. We implement RepNet on node.js, one of the most commonly used platforms for networked interactive applications. node's single threaded event-loop and non-blocking I/O make flow replication highly efficient. Performance evaluation on a real network testbed and in Mininet reveals that RepNet is able to reduce the tail latency of mice flows, as well as application completion times, by more than 50%.

Research Area(s)

  • Data center networks, Electronic mail, flow replication, latency, Mice, Performance evaluation, Production, Switches, Topology