The parallel and distributed simulation field has evolved and grown from its origins in the 1970s and 1980s and remains an active field of research to this day. A brief overview of research in the field is presented. Future research topics are explored including areas such as problem-driven simulation of large-scale systems and complex networks, exploitation of graphical processing unit hardware and cloud computing environments, predictive online simulation for system management and optimization, power and energy consumption in mobile platforms and data centers, and composition of heterogeneous simulations.

https://dl.acm.org/doi/pdf/10.1145/2866577

Research Challenges in Parallel and Distributed Simulation

New trends in parallel and distributed simulation: From many-cores to Cloud Computing

Network emulation brings together the strengths of network simulation (scalability, modeling flexibility) and real-world software prototypes (realistic analysis). Unfortunately network emulation fails if the simulation is not real-time capable, e.g., due to large scenarios or complex models. So far, this problem has generally been addressed by providing massive computing power to the simulation, which is often too costly or even infeasible.In this paper we present SliceTime, our platform for scalable and accurate network emulation. It enables the precise evaluation of arbitrary networking software with event-based simulations of any complexity by relieving the network simulation from its real-time constraint. We achieve this goal by transparently matching the execution speed of virtual machines hosting the software prototypes with the network simulation. We demonstrate the applicability of SliceTime in a large-scale WAN scenario with 15000 simulated nodes and show how our framework eases the analysis of software for 802.11 networks.

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SliceTime: a platform for scalable and accurate network emulation

The advancement of software-defined networking (SDN) technology is highly dependent on the successful transformations from in-house research ideas to real-life products. To enable such transformations, a testbed offering scalable and high fidelity networking environment for testing and evaluating new/existing designs is extremely valuable. Mininet, the most popular SDN emulator by far, is designed to achieve both accuracy and scalability by running unmodified code of network applications in lightweight Linux Containers. However, Mininet cannot guarantee performance fidelity under high workloads, in particular when the number of concurrent active events is more than the number of parallel cores. In this project, we develop a lightweight virtual time system in Linux container and integrate the system with Mininet, so that all the containers have their own virtual clocks rather than using the physical system clock which reflects the serialized execution of multiple containers. With the notion of virtual time, all the containers perceive virtual time as if they run independently and concurrently. As a result, interactions between the containers and the physical system are artificially scaled, making a network appear to be ten times faster from the viewpoint of applications within the containers than it actually is. We also design an adaptive virtual time scheduling subsystem in Mininet, which is responsible to balance the experiment speed and fidelity. Experimental results demonstrate that embedding virtual time into Mininet significantly enhances its performance fidelity, and therefore, results in a useful platform for the SDN community to conduct scalable experiments with high fidelity.

/pdf/vt-mininet-virtual-time-enabled-mininet-for-scalable-and-4fj9ozbo2l.pdf

VT-Mininet: Virtual-time-enabled Mininet for Scalable and Accurate Software-Define Network Emulation

We present TimeKeeper: a simple lightweight approach to embedding Linux containers (LXC) in virtual time. Each container can be directed to progress in virtual time either more rapidly or more slowly than the physical wall clock time. As a result, interactions between an LXC and physical devices can be artificially scaled, e.g., to make a network appear to be ten times faster with respect to the software within the LXC than it actually is. Our approach also supports synchronized (in virtual time) emulation, by grouping LXCs together into an experiment where the virtual times of containers are kept synchronized, even when they advance at different speeds. This has direct application to the integration of emulation and simulation within a common framework.

TimeKeeper: a lightweight virtual time system for linux

The ability to establish an objective comparison between high-performance TCP variants under diverse networking conditions and to obtain a quantitative assessment of their impact on the global network traffic is essential to a community-wide understanding of various design approaches. Small-scale experiments are insufficient for a comprehensive study of these TCP variants. We propose a TCP performance evaluation testbed, called SVEET, on which real implementations of the TCP variants can be accurately evaluated under diverse network configurations and workloads in large-scale network settings. This testbed combines real-time immersive simulation, emulation, machine and time virtualization techniques. We validate the testbed via extensive experiments and assess its capabilities through case studies involving real web services.

SVEET! a scalable virtualized evaluation environment for TCP

The Global Environment for Network Innovations (GENI) is a community-driven research and development effort to build a collaborative and exploratory network experimentation platform -- a "virtual laboratory'' for the design, implementation and evaluation of future networks. The PrimoGENI project enables real-time network simulation by extending an existing network simulator to become part of the GENI federation to support large-scale experiments involving physical, simulated and emulated network entities. In this paper, we describe a novel design of PrimoGENI, which aims at supporting realistic, scalable, and flexible network experiments with real-time simulation and emulation capabilities. We present a flexible emulation infrastructure that allows both remote client machines and local cluster nodes running virtual machines to seamlessly interoperate with the simulated network running within a designated "slice'' of resources. We show the results of our preliminary validation and performance studies to demonstrate the capabilities and limitations of our approach.

PrimoGENI: Integrating Real-Time Network Simulation and Emulation in GENI

In this paper, we propose SEA-MAC, a new energy aware medium access control (MAC) protocol for wireless sensor networks for environmental monitoring applications. The proposed MAC scheme is specifically designed for wireless sensor networks which have periodic traffic. In our MAC scheme, the duty cycle is shortened by making nodes wake up only when an environmental sample is taken. Also in SEA-MAC, only the base station can start and maintain synchronization. Consequently, the synchronization is unique in the whole network. The proposed SEA-MAC protocol is tested using simulations and real measurements on the implementations using mica2 motes

/pdf/sea-mac-a-simple-energy-aware-mac-protocol-for-wireless-314na896rm.pdf

SEA-MAC: A Simple Energy Aware MAC Protocol for Wireless Sensor Networks for Environmental Monitoring Applications

A testbed capable of representing detailed operations of complex applications under diverse large-scale network conditions can be extremely helpful for investigating potential system design and implementation problems, and studying application performance issues, such as scalability and robustness, even before the applications are deployed in a real environment. We introduce a novel method that combines high-performance large-scale network simulation and high-fidelity network emulation, and thereby enables real instances of network applications and protocols to run in real operating environments, and be tested under large-scale simulated network settings. In our approach, network simulation and emulation form a symbiotic relationship, through which they are synchronized for an accurate representation of the large-scale traffic behavior. We introduce a model downscaling method, along with an efficient queuing model and a traffic reproduction technique, which can significantly reduce the synchronization overhead and improve computational efficiency, while maintaining the accuracy of the system. We validate our approach with extensive experiments via simulation and with a real-system prototype.

Leveraging symbiotic relationship between simulation and emulation for scalable network experimentation

The Global Environment for Network Innovations (GENI) is a community-driven research and development effort to build a collaborative and exploratory network experimentation platform—a ‘virtual laboratory’ for the design, implementation, and evaluation of future networks. The PrimoGENI project enables real-time network simulation by extending an existing network simulator to become part of the GENI federation to support large-scale experiments involving physical, simulated, and emulated network entities. In this paper, we describe a novel design of PrimoGENI, which aims at supporting realistic, scalable, and flexible network experiments with real-time simulation and emulation capabilities. We present a flexible emulation infrastructure that allows both remote client machines, local cluster nodes running virtual machines, and external networks to seamlessly interoperate with the simulated network running within a designated ‘slice’ of resources. We present the results of our preliminary validation and performance studies to demonstrate the capabilities as well as limitations of our approach.

https://link.springer.com/content/pdf/10.1057%2Fjos.2012.5.pdf

Miguel A. Erazo

Papers

SVEET! a scalable virtualized evaluation environment for TCP

PrimoGENI: Integrating Real-Time Network Simulation and Emulation in GENI

SEA-MAC: A Simple Energy Aware MAC Protocol for Wireless Sensor Networks for Environmental Monitoring Applications

Leveraging symbiotic relationship between simulation and emulation for scalable network experimentation

PrimoGENI for hybrid network simulation and emulation experiments in GENI