A study of networking software induced latency

For long time, high-speed packet processing has been reserved for specialized hardware devices since software based solutions were not able to achieve the required performance. However, off-the-shelf packet processing hardware and software improved over the last years, which is why software based solutions cope with high-speed traffic nowadays. Due to the flexibility of software there is a trend towards doing packet processing in software, e.g. using OpenFlow or virtual switches. Although packet processing in software offers many capabilities, the complexity of such software bases solutions makes it hard to evaluate, optimize, or predict the networking performance of servers, end user hosts, or routers. We present a study that investigates the packet latency caused by the packet processing in the Linux network stack. We develop a simulation model in ns-3 for packet processing via the Linux network stack that helps understanding of its performance implications. We validate our simulation model based on measurements with nanosecond accuracy and software profiling.