Distributed Simulation for Digital Twins of Large-Scale Real-World DiffServ-Based Networks

TL;DR

This paper introduces Quaint, a novel distributed simulation toolkit leveraging optimistic PDES for detailed DiffServ network modeling, achieving significant speedups over traditional simulators in large-scale network analysis.

Contribution

The paper presents Quaint, a new simulation toolkit with an innovative event-handling model for DiffServ networks, enabling efficient large-scale network simulation with high speedup and scalability.

Findings

Quaint achieves a 53x speedup in sequential mode compared to OMNeT++/INET.

Distributed mode of Quaint achieves a 232x speedup.

Scalability analysis indicates effective workload-aware model partitioning.

Abstract

Digital Twin technology facilitates the monitoring and online analysis of large-scale communication networks. Faster predictions of network performance thus become imperative, especially for analysing Quality of Service (QoS) parameters in large-scale city networks. Discrete Event Simulation (DES) is a standard network analysis technology, and can be further optimised with parallel and distributed execution for speedup, referred to as Parallel Discrete Event Simulation (PDES). However, modelling detailed QoS mechanisms such as DiffServ requires complex event handling for each network router, which can involve excessive simulation events. In addition, current PDES for network analysis mostly adopts conservative scheduling, which suffers from excessive global synchronisation to avoid causality problems. The performance analysis of optimistic PDES for real-world large-scale network topology and complex QoS mechanisms is still inadequate. To address these gaps, this paper proposes a simulation toolkit, Quaint, which leverages an optimistic PDES engine ROSS, for detailed modelling of DiffServ-based networks. A novel event-handling model for each network router is also proposed to significantly reduce the number of events in complex QoS modelling. Quaint has been evaluated using a real-world metropolitan-scale network topology with 5,000 routers/switches. Results show that compared to the conventional simulator OMNeT++/INET, even the sequential mode of Quaint can achieve a speedup of 53 times, and the distributed mode has a speedup of 232 times. Scalability characterisation is conducted to portray the efficiency of distributed execution, and the results indicate the future direction for workload-aware model partitioning.