The Impact of Software-based Virtual Network in the Public Cloud

Today's cloud network consists of sophisticated virtual networks, and a virtual switch is a key element of these networks. Although there is tremendous interest in measuring cloud network performance, little is known about the impact of software-based virtual network on latency. In this paper, we conduct the impact of virtual network on latency in the public cloud based on OpenStack. We measured the throughput of VMs and simultaneously captured their packets on hosts. We analyzed the traces by using well-known metrics, such as throughput and RTT, and investigated the abrupt fluctuation of latency called as 'the burstiness of latency'. We quantitatively clarify the impact of software-based virtual network on latency. In our public cloud, the latency is approximately 35.2% of RTT and 10% of burstiness mainly contributes to the increased RTT. The total latency was increased by the receiving side regardless of data and ACK paths. Our analysis results, discussions, and implications can not only help cloud researchers and developers design the next generation of software-based virtual network but can also help cloud operators improve the performance of virtual network.