Motivation

The growth of the number of hosts connected to the Internet and of new applications increased the importance of research and development of Quality of Service (QoS)-based networks. In order to optimize the proposal and the validation of new QoS architectures and technologies, simulation seems to be the best solution when considering the deployment efforts, cost and scalability. Unfortunately, the existing platforms and tools for simulating QoS-based Networks either do not support all the architectures and technologies or do not fully support their characteristics. Basically, a simulation life-cycle can be divided into three phases: specification of the scenario, simulation of the events and analysis of the results of the simulation. This work presents a platform for the specification of networks scenarios supporting QoS and multicast, which can be simulated using ns-2. This platform provides the author with the possibility of covering all the three phases of the simulation life-cycle on-the-fly.

Visual Network Simulator

The Visual Network Simulator (VNS) tool, centered on the NSG2 tool capabilities, was developed aiming to facilitate the creation of network simulation scenarios to be executed over ns-2. Two important innovations of VNS, compared to other similar tools are: (1) the support to Differentiated Services (DiffServ) scenarios, and, (2) it provide a simple and intuitive set of icons to represent the components of a network. Examples of these icons are the hosts, the routers and an Internet cloud, each with a different symbol. Some others important functionalities of VNS were also taken into account, such as:
  • Adding and configuration of links, agents and traffic sources;
  • Modeling network scenarios with support to multicast;
  • Selection of a dynamic routing protocol;
  • Definition of the simulation output as an animation and/or graphics;
  • Edition of the Tcl script generated, and;
  • Saving the defined simulation scenario.

Screen Shots

Some Topologies

Differentiated Services configuration

General Simulation Configuration and TCL edition

Download

This tool can be downloaded without any warranty and under the Creative Commons License in the links below.
The pre-requesites are Java Virtual Machine® 5 installed. The scenarios where tested under ns-2 v2.31.

  • Linux version here;
  • Windows version here.
CC-GNU LGPL
LGPL http://creativecommons.org/licenses/LGPL/2.1/ 2.1

Author

Ms.C. Ricardo Plácido 
This work was done as a Master Thesis project in University of Madeira under the supervision of Prof. Paulo Sampaio. Other participants: Eduardo Marques.
Any questions about VNS can be sent to vns [ internet symbol ] apus [dot] uma [dot] pt.