Model-driven network emulation with virtual time machine

Jason Liu, Raju Rangaswami, Ming Zhao
2010 Proceedings of the 2010 Winter Simulation Conference  
We present VENICE, a project that aims at developing a high-fidelity, high-performance, and highly-controllable experimental platform on commodity computing infrastructure to facilitate innovation in existing and futuristic network systems. VENICE employs a novel model-driven network emulation approach that combines simulation of large-scale network models and virtual-machine-based emulation of real distributed applications. To accurately emulate the target system and meet the computation and
more » ... mmunication requirements of its individual elements, VENICE adopts a holistic machine and network virtualization technique, called virtual time machine, in which the time advancement of simulated and emulated components are regulated in complete transparency to the test applications. In this paper, we outline the challenges and solutions to realizing the vision of VENICE. A HARMLESS NECESSARY CAT We classify existing experimental networking research testbeds into physical, emulation, and simulation testbeds. Emulation testbeds combine physical testbeds and emulation, and provide the ability to conduct extensive live experiments. Although emulation allows a certain level of flexibility, the emulated network conditions are inherently restricted by physical limitations (such as nodal processing speed, link bandwidth and latency) and cannot be scaled up beyond the capabilities of the underlying physical infrastructure. Comparatively, network simulation is effective at capturing high-level design issues, answering what-if questions, and investigating complex system behaviors, such as multiscale interactions, self-organizing characteristics, and emergent phenomena. However, simulation fairs poorly in other aspects, particularly in its operational realism. Further, simulation development is both labor-intensive and error-prone; reproducing realistic network topology, traffic and diverse operational conditions in simulation is known to be a substantial undertaking. In this position paper, we describe our ongoing efforts on the VENICE project (Virtual Emulation Network Infrastructure for Commodity Environments), which aims to combine the advantages of simulation and emulation techniques to provide a high-fidelity, high-performance, and highly-controllable experimental platform for large-scale network experiments. The central thrust of this project is a novel model-driven network emulation approach for conducting large-scale network experiments. We pursue holistic machine and network virtualization techniques that allow execution of network simulation models and emulation of real implementations of network protocols and distributed applications under a coordinated virtual time-line. VENICE consists of simulated networks connecting to emulated hosts sandboxed inside virtual machines running real implementations of network applications or network protocols (e.g., router software). Traffic generated from the applications is conducted by the virtual network with appropriate delays and losses according to both simulated and emulated network conditions. Our goal with VENICE is to enable network experimental testbeds that adhere to arbitrary, user-defined "virtual" network and machine infrastructure specifications. To do so, we need to address fundamental challenges related to accuracy, scalability, and controllability. To create a highly accurate virtual network testbed, we propose a unified machine and network virtualization scheme, called Virtual Time Machine (VTM), to both allocate compute resources, regulate the advancement of time within simulated and emulated entities, and control the delivery of network events. These capabilities ensure correct emulation of the target system with specific user-specified computation and communication requirements. VTM involves transparently and dynamically dilating or contracting virtual time experienced by the applications running on individual virtual machine relative to the real passage of time according to the model requirement 688 978-1-4244-9864-2/10/$26.00
doi:10.1109/wsc.2010.5679120 dblp:conf/wsc/LiuRZ10 fatcat:iwfpcjgtezglrhaf4bqgic7kgu