Network Emulation Support in ns-3 Through Kernel Bypass Techniques

The network emulation support in ns-3 enables the interaction with real devices allowing the integration of a simulated node or network in an emulated scenario. Also, the network emulation support in a simulator is fundamental to validate its models. For both purposes, the emulation capabilities in ns-3 must reproduce the real host incoming and outgoing networking paths to increase the emulation credibility. In this work, we present our effort to introduce kernel bypass techniques in ns-3 to improve the network emulation support. We used netmap, a fast packets processing framework, to bypass the host networking stack and gain direct access to network device. We designed and introduced in ns-3 a new device to perform emulation that uses the netmap primitives to read and write packets on a real device. We carried out a preliminary benchmark of our device in an ethernet back-to-back scenario. The results show a more accurate performance in terms of delay and more realistic distributions of packets backlog in traffic-control of ns-3 and of packets inflight.