Nicolas Larrieu

Non-Gaussian and Long Memory Statistical Characterizations for Internet Traffic with Anomalies

The goals of the present contribution are twofold. First, we propose the use of a non-Gaussian long-range dependent process to model Internet traffic aggregated time series. We give the definitions and intuition behind the use of this model. We detail numerical procedures that can be used to synthesize artificial traffic exactly following the model prescription. We also propose original and practically effective procedures to estimate the corresponding parameters from empirical data. We show that this empirical model relevantly describes a large variety of Internet traffic, including both regular traffic obtained from public reference repositories and traffic containing legitimate (flash crowd) or illegitimate (DDoS attack) anomalies. We observe that the proposed model accurately fits the data for a wide range of aggregation levels. The model provides us with a meaningful multiresolution (i.e., aggregation level dependent) statistics to characterize the traffic: the evolution of the estimated parameters with respect to the aggregation level. It opens the track to the second goal of the paper: anomaly detection. We propose the use of a quadratic distance computed on these statistics to detect the occurrences of DDoS attack and study the statistical performance of these detection procedures. Traffic with anomalies was produced and collected by us so as to create a controlled and reproducible database, allowing for a relevant assessment of the statistical performance of the proposed (modeling and detection) procedures

A Mobility Model For UAV Ad hoc Network

With the technological advances, there is an increasing attention on micro-UAVs in the military area as well as in the civilian domain. They are used as swarm (several UAVs) forming a UAS (Unmanned Aircraft System) since they are relatively cheap and offer better performance than one aircraft. The UAVs, in a UAS, have to exchange information with each other and with the control station in order to create a clear vision of the swarm situation and the task performance. This exchange is made possible by the application of an ad hoc network between UAVs which is a challenging issue because of the node mobility, the network topology change, and the operation communication requirements in term of quality of service (delay, throughput or loss rate for instance). This paper presents a realistic mobility model designed for UAV ad hoc networks. since evaluating the performances of ad hoc protocols is an important step in order to predict possible problems that can affect the system in the real environment. This mobility model behavior is compared to the well-known mobility model behavior Random-Way Point. It is also compared to real movements traces using several metrics.

Internet Traffic Characterization – An Analysis of Traffic Oscillations

Internet traffic has been changing a lot since few years in particular with the arrival of new P2P applications for exchanging audio files or movies and nowadays the knowledge we have on it is quite limited. Especially, new applications and new traffic are creating a lot of troubles and performance issues. Based on some traffic traces captured in the framework of the METROPOLIS network monitoring project, this paper exhibits the highly oscillating nature of Internet traffic, thus explaining why it is almost impossible nowadays to guarantee a stable QoS in the Internet, and also that such oscillations provoke a huge decrease of the global network QoS and performance. This paper then demonstrates that traffic oscillations can be characterized by the Hurst (LRD) parameter. In particular, this demonstration relies on a comparative study of Internet traffic depending on the transport protocol used to generate it. It is then shown that using TFRC – a congestion control mechanism whose purpose deals with providing smooth sending rates for stream oriented applications – instead of TCP, makes traffic oscillations and LRD almost disappear. This result, i.e. limiting as much as possible the oscillations of traffic sources in the Internet, then gives research directions for future Internet protocols and architectures.

Evaluation of active measurement tools for bandwidth estimation in real environment

Available bandwidth - as well as capacity or achievable bandwidth - on a path or a link is one of the very important parameters to measure or estimate in a network: it is of high interest for many networking functions (routing, admission and congestion control, load balancing, etc). Active probing techniques provide the easiest and the more flexible approach, for estimating available bandwidth. In addition, they can be used for different network technologies or structures. Many techniques and tools for available bandwidth estimation appeared recently, but little attention has been given to the accuracy of the estimated values in the real Internet, most of previous studies focusing on validating the accuracy of these tools on local platform. Therefore, this paper deals with evaluating the accuracy of active estimation tools in the real wide area Internet. We use passive monitoring tools for this purpose. We then built a platform combining active and passive equipments, and define a methodology for evaluating active probing techniques using passive tools. The passive evaluation relies on DAG system cards that represent references for such kind of measurements. This paper then discusses the results we got in the different experiments with different tools. In particular, we use traffic generators for changing the characteristics of the traffic on the Internet paths, which we are making our measurements on. It is useful for analyzing the accuracy of active estimation tools according to network and traffic conditions.

Secure routing protocol design for UAV Ad hoc NETworks

UAV Ad hoc NETworks (UAANETs) can be defined as a new form of ad hoc networks in which nodes are Unmanned Aerial Vehicles (UAVs) and Ground Control Station (GCS). Compared to the usual Mobile Ad hoc NETwork (MANET), this new network paradigm has some unique features and brings specific challenges such as node mobility degree, network connectivity patterns, delay-sensitive applications and network security. Indeed, from routing point of view, none of the several UAANET routing protocols proposed in the literature have been designed with security in mind. This lack of consideration can make the certification of UAANETs difficult to obtain. In this paper, we present our vision of such a challenge and the research that we are conducting. The aim is to propose an original secure routing protocol for UAANETs using a Model Driven Development (MDD) approach which will ease the certification of final UAV products. The first preliminary results concerning our secure-routing protocol design will be presented. This paper describes our ongoing research which will provide secure communications for UAV ad hoc networks at the end of the SUANET (Secure Uav Ad-hoc NETwork) project.

An aeronautical data link security overview

This paper reviews existing security mechanisms for aeronautical data link communication: current support and availability of such features are described. With an Open Systems Interconnection (OSI) reference model-driven analysis, each solution is classified and analyzed according to the layer where security is deployed and a relevant taxonomy is proposed. Moreover, advantages, drawbacks, and possible threats of every security mechanisms previously introduced are discussed. According to this security infrastructure overview, a proposal for an efficient security architecture adapted to the aeronautical context is made for future studies. Satellite communication-based system specific problematic is taken into account with a constraint bandwidth and the need of reduced overhead for any additional mechanisms.

An ADS-B Based Secure Geographical Routing Protocol for Aeronautical Ad Hoc Networks

Data communications are currently considered as a key enabler in the modernization of the aviation industry. Current aircraft are becoming equipped with advanced data communication capabilities, whereas the aviation stakeholders are seeking for new communication solutions to face the increasing air traffic load. Thus, we can expect to see large scale aeronautical ad hoc networks which could be used to meet those needs in the near future. This paper discusses the security issues to be addressed in routing protocols defined in the scope of aeronautical ad hoc networks. Existing routing approaches are briefly discussed, then a secure geographical routing protocol for future aircraft ad hoc networks is proposed. Finally the protocol is formally verified and its performances are discussed.

Emulation-Based Performance Evaluation of Routing Protocols for Uaanets

UAV Ad hoc NETwork (UAANET) is a subset of the well known Mobile Ad-hoc NETworks (MANETs). It consists of forming an ad hoc network with multiple small Unmanned Aerial Vehicles (UAVs) and the Ground Control Station (GCS). Similar to MANETs, the UAANET communication architecture is infrastructure-less and self-configuring network of several nodes forwarding data packets. However, it also has some specific features that brings challenges on network connectivity. Consequently, an adapted routing protocol is needed to exchange data packets within UAANETs. In this paper, we introduce a new hybrid experimental system that can evaluate different types of adhoc routing protocols under a realistic UAANET scenario. It is based on virtual machines and the Virtual mesh [1] framework to emulate physical aspects.We evaluated AODV, DSR and OLSR efficiency in a realistic scenario with three UAVs scanning an area. Our results show that AODV outperformed OLSR and DSR.

Measurement based networking approach applied to congestion control in the multi-domain Internet

How to provide quality of service (QoS), has been a major issue for the Internet for the past decade. Though many proposals have been put forward in the areas of differentiated and guaranteed services, none have met the needs of users and operators. Efforts have been stymied by the complexity of the Internet, its myriad systems of interconnection, and by the technological heterogeneity of these systems. They have also run up against poor general knowledge of traffic characteristics that are largely unknown. In particular, recent monitoring projects showed that Internet traffic exhibited huge variations, leading to non-stationary traffic, and thus making difficult to guarantee a stable QoS. This paper then proposes a new measurement based architecture (MBA) and its related mechanisms (as the measurement signaling protocol (MSP) for instance, aiming at signaling to network components network information in real time) suited for coping with actual non-stationary traffic, and with the actual split topology of the Internet for which each domain provides a particular QoS. The idea of our measurement based networking (MBN) approach relies on a real time analysis of traffic characteristics and QoS evolution, and on the design of mechanisms able to adapt their reactions accordingly. The benefits of MBN are illustrated on a case study: a new measurement based congestion control (MBCC) which aims at smoothing traffic (making it more stable and stationary) and optimizing the use of network resources. Some preliminary results, based on NS-2 simulations, show the perfect suitability of this new mechanism for improving traffic characteristics and multi-domain QoS in the Internet, given the complexity and variability of actual traffic.

Aeronautical communication transition from analog to digital data: A network security survey

Abstract The objective of this paper is to present a comprehensive survey of security challenges in aeronautical data communication networks. The civil aviation industry is currently going through an evolution of the air traffic management system. The aviation communication technologies are progressively shifting towards the use of digital data instead of analog voice for traffic control, airline business, and passenger onboard entertainment systems. This paper illustrates the cause-to-effect chain link starting from the modernization of the aeronautical communication systems and leading to the network security concern in the civil aviation. The general threats to air–ground communication are depicted and then categorized. The paper gives an overview of the civil aviation industry efforts for securing the future aeronautical data communications. The security mechanisms and protocols proposed for this purpose are discussed. Open research issues and challenges that have to be addressed in the security of current and future aeronautical data communication networks are presented in detail. The paper concludes with some improvement directions which can help to address those security issues. This survey can be used as a reference guide to first understand the factors that urge both the research community and the aviation industry to be concerned about network security in future aeronautical data communications. Also, it can be used as a first reading to have a global overview of network security issues, challenges and potential solutions in air–ground communication networks.