A Network Bandwidth Limitation with the DEMU Network Emulator

A network emulator is crucial for systematically and reproducibly testing the performance of real applications, especially for network quality-sensitive applications. Network emulators are classified into two types, which are hardware-based and software-based emulators. Hardware-based emulator achieves high accuracy but a special purpose hardware equipment is expensive. Recently, software-based emulator practically used in several use cases and the accuracy is getting improved due to the high performance packet processing framework like DPDK. DEMU is a network emulator based on DPDK. The previous version of DEMU only emulated network latency and packet loss. In this paper, we introduce the bandwidth limitation feature into DEMU to emulate network bandwidth, because it is another important network characteristic. We demonstrate two bandwidth limitation methods on DEMU, which are token bucket and gap packet. Through experiments, we confirmed that DEMU is able to emulate the bandwidth with low error rate of less than 1%.