Network Analysis and Routing eVALuation, referenced as NARVAL has been designed on top of the Scilab environment. It has been created at the University of Luxembourg within the Interdisciplinary Centre for Security, Reliability and Trust (SnT). The Centre carries out interdisciplinary research and graduate education in secure, reliable, and trustworthy ICT systems and services. This Scilab External Module is focusing on the analysis of network protocols and algorithms. Each network of communicating devices such as computers, phones or sensors, needs to follows specific rules in order to organize and control the data exchange between source and destination nodes. Communication protocols enable to discover the network topology, and to propagate the data traffic between network entities. The main goal of our toolbox is to provide a complete software environment enabling the understanding of available communication algorithms, but also the design of new schemes in order to evaluate and improve the traffic behavior and distribution on network topologies defined by the user. NARVAL permits to generate random topologies according to various algorithms such as Locality, Waxman, Barabasi-Albert and hierarchical models. The user can also design his own topology by providing nodes' coordinates, visualization parameters, and also links' information that are necessary for path calculation. The combination of these functions enables to build a large range of topologies with distinct routing properties. The NARVAL module permits to study the impact of routing algorithms on the effectiveness of transmission protocols used by data communications on a defined network topology. We provide a set of basic functions in order to create network graphs, compute routing algorithms (AODV, BFS, DFS, Bellman-Ford, Dijkstra, Flood, Floyd-Warshall, Multiple Paths, RPL, ARC, etc.) on them and finally make statistical analysis on the efficiency of data communications. The mobility of nodes (Mobile/Vehicular Ad hoc NETwork MANET/ VANET) is also ...