Theoretical applications and practical network algorithms are not very cost-effective, and most of the algorithms in the commercial market are implemented in the cutting-edge devices. Open-source network simulators have gained importance in recent years due to the necessity to implement network algorithms in more realistic scenarios with reasonable costs, especially for educational purposes and scientific researches. Although there have been various simulation tools, NS2 and NS3, OMNeT++ is more suitable to demonstrate network algorithms because it is convenient for the model establishment, modularization, expandability, etc. OMNeT++ network simulator is selected as a testbed in order to verify the correctness of the network algorithms. The study focuses on the algorithms based on centralized and distributed approaches for multi-hop networks in OMNeT++. Two network algorithms, the shortest path algorithm and flooding-based asynchronous spanning tree algorithm, were examined in OMNeT++. The implementation, analysis, and visualization of these algorithms have also been addressed.
TopThe Comparison Of Network Simulators
In recent years various comparisons between network simulators are done (Weingartner et al., 2009; Chaudhary et al., 2012; Xian et al., 2008). We are briefly defining some of the most popular network simulators and we are giving comparison between them shown in Table 1 (Kabir et al, 2014).
NS2 (Network Simulator v2): NS2 which is a discrete event simulator with a focus on network research is used for simulating TCP, routing and multicast protocols over wireless and wired networks (Issariyakul and Hossain, 2009).
NS3 (Network Simulator v3): NS-3 which is a free software for simulating Internet systems is publicly available for research, development and educational purposes. Various virtual nodes can be created by using NS3 (Riley and Henderson, 2010). Various auxiliary classes, devices, internet stacks or applications can be installed on the previously created nodes. Connections between nodes such as PointToPoint, Wireless, CSMA can be simulated by means of NS3. C++ or Python languages are used to code the simulation.
Opnet: Opnet Network Simulator which is an event-based high-level network simulation tooloffers a large number of project scenarios (Chang X., 1999).
JSim: JSim is a simulation system for generating and analyzing quantitative numeric models. Although its main focus is on biomedicine and physiology, its computational engine is also applicable in many other scientific fields (Sobeih et al., 2006).
QualNet: The QualNet® is a network simulation simulating the behavior of the communication network. It is used as a planning, testing, and a training tool (“QualNet - Network Simulation Software | SCALABLE Networks,” n.d.).