The remarkable growth of the Internet infrastructure and the increasing heterogeneity of applications and users' behavior make more complex the manageability and monitoring of ISP networks and raises the cost of any new deployment. The main consequence of this trend is an inherent disagreement between existing monitoring solutions and the increasing needs of management applications. In this context, we present the design of an adaptive centralized architecture that provides visibility over the entire network through a network-wide cognitive monitoring system. Practically, given a measurement task and a constraint on the volume of collected information, the proposed architecture drives the sampling rates on the interfaces of network routers to achieve the maximum possible accuracy, while adapting itself to any change in network traffic conditions. We illustrate our work with an accounting application whose purpose is to estimate the volume of aggregate flows across a backbone transit network. The paper provides a global study of the functioning of the proposed system and the impact of the different parameters on its behavior. The performance of our system is validated in typical scenarios over an experimental platform we developed for the purpose of the study.

It is of utmost importance for the network research community to have access to tools and testbeds to explore future directions for Internet traffic monitoring and engineering. Although many experimental solutions exist today, they tend to be highly specialized or to have a limited availability and openness. Through this work, we outline the monitoring capabilities limitations of these facilities and we present our emulation platform for network wide traffic monitoring as an answer to these limitations. Our platform presents a new approach for the emulation of Internet traffic and for its monitoring across the different routers. Through our solution, we put at the disposal of users a real traffic emulation service coupled to a set of libraries and tools capable of Cisco NetFlow data export and collection, the overall destined to run advanced applications for network wide traffic monitoring and optimization.

In 4G networks, various wireless access technologies will be integrated into a heterogeneous network based on an IP core network infrastructure. Thus, numerous works focus on mobility and vertical handover management to allow multiple-interfaces mobile terminals to roam seamlessly between these access networks. The different handoff schemes can be classified into three approaches according to where the decision to handoff is made: within the terminal, the network or thanks to a collaboration between them. However, these approaches still present some drawbacks; namely the problem of resource management whenever the handover is controlled by the mobile terminal (MT) and the problem of scalability and complexity whenever the handover is rather decided by the network. In this paper, we propose a new approach that explicitly takes into account management requirements, the current resource usage and user preferences. Furthermore, our solution provides means to select the "best-suited" network for each application according to its expectations in terms of QoS. A feasibility study of our solution is then conducted on a single mobile terminal by using typical scenarios and applying various algorithms to evaluate their behaviors.