  A key enabling technology of NFV is software dataplane, which has attracted
much attention in both academia and industry recently. Yet, till now there is
little understanding about its performance in practice. In this paper, we make
a benchmark measurement study of NFV software dataplanes in terms of packet
processing capability, one of the most fundamental and critical performance
metrics. Specifically, we compare two state-of-the-art open-source NFV
dataplanes, SoftNIC and ClickOS, using commodity 10GbE NICs under various
typical workloads. Our key observations are that (1) both dataplanes have
performance issues processing small (<=128B) packets; (2) it is not always best
to put all VMs of a service chain on one server due to NUMA effect. We propose
resource allocation strategies to remedy the problems, including carefully
adding CPU cores and vNICs to VMs, and spreading VMs of a service chain to
separate servers. To fundamentally address these problems and scale their
performance, SoftNIC and ClickOS could improve the support for NIC queues and
multiple cores.
