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This paper describes a new real-time urban monitoring system. The system uses the Localizing and Handling Network Event Systems (LocHNESs) platform developed by Telecom Italia for the real-time evaluation of urban dynamics based on the anonymous monitoring of mobile cellular networks. In addition, data are supplemented based on the instantaneous positioning of buses and taxis to provide information...
A centralized impairment-aware lightpath restoration scheme is experimentally demonstrated. Through the implementation of the QoT estimator module on FPGA technology, restoration times of 1.36 s are achieved for the high priority traffic class.
Network performance measurements have been broadly used in order to debug and to assess the reliability of the network. In general performance measurement is a resource consuming process, which in practice derives in hardly scalable systems. However, in order to control and monitor network resource usage and to assess the quality of multimedia traffic, it is broadly accepted that efficient and scalable...
We address the problem of optimizing the use of Network monitoring tools, such as Netflow, on a large IP network. We formulate a convex optimization problem which allows one to handle, in a unified framework, the combinatorial problem of selecting the “best” set of interfaces on which Netflow should be activated, and the problem of finding the optimal sampling rates of the network-monitoring tool...
The access link quality experienced by the end users depends on the amount of traffic and on the presence of network anomalies. Different techniques exist to detect anomalies, but little attention has been devoted to quantify the access link quality and to which extent network anomalies affect the end user's access link experience. We refer to this aspect as the impact factor of the anomaly, that...
The problem of detecting packet flows between two nodes in a wireless network is considered. Especially, the transmission timings of two nodes are recorded, and their transmission rates can be time-varying (piecewise constant). Based on the timing measurements, our objective is to detect the presence of packet flows between them. Two different scenarios are considered; the first is that a flow may...
Call Admission Control (CAC) is recognized as one of the key strategies to achieve satisfactory QoS support for VoIP over IEEE 802.11 WLANs. However, most of the prior CAC solutions for VoIP over WLAN are centralized, and the few distributed CAC schemes proposed so far do not account for issues such as the loss of channel time due to medium contention and the coexistence of VoIP traffic with background...
In this work we consider the problem of monitoring information streams for anomalies in a scalable and efficient manner. We study the problem in the context of network streams where the problem has received significant attention. Monitoring the empirical Shannon entropy of a feature in a network packet stream has previously been shown to be useful in detecting anomalies in the network traffic. Entropy...
The random packet sampling method is the simplest methodology for reducing the amount of packets that the network monitoring system has to process. However, the accuracy of anomaly detection is affected by the fact that this method biases a large IP flow. In order to reduce the impact of sampled traffic on network anomaly detecting, an adaptive traffic sampling method is proposed. This method is developed...
Summary form only given. The evolution of optical networks should aim at improved cost economics, reduced operations efforts, scalability and adaptation to the future services and application requirements. Considering the evolution trend of optical networks, the core networks of the future will have a translucent and eventually transparent optical network structure. The realization of dynamic and...
The market growth of VoIP infrastructures and services is pushing towards additional facilities to enrich service offer in an open way, thus representing also a differentiating aspect and a competitive advantage for service providers. We claim that the proactive provisioning of estimations about runtime VoIP quality is a crucial facility still missing in VoIP services. For instance, such a facility...
This paper presents a purely empirical approach to estimating the effective bandwidth of aggregated traffic flows independent of traffic model assumptions. The approach is shown to be robust when used in a variety of traffic scenarios such as both elastic and streaming traffic flows of varying degrees of aggregation. The method then forms the basis of two quality of service related traffic performance...
In the context of a collaborating surveillance system for active TCP sessions handled by a networking device, we consider two problems. The first is the problem of protecting a flow table from overflow and the second is developing an efficient algorithm for estimating the number of active flows coupled with the identification of "heavy-hitter" TCP sessions. Our proposed techniques are sensitive...
Summary form only given: This research work presents and compares two NoC power estimation models, one based on the volume of information transmitted in the network, and another based on the transmission rates of each router. NoC power/energy volume-base estimation model is based in the volume of information transmitted through the network, and have been widely used as an option to commercial power...
Current popular sampling algorithms canpsilat provide accurate approximation of true character under the circumstance of network traffic bursting. In the paper, we develop an adaptive network traffic sampling methodology (MANFC-AT) based on aggregated time-serial evolution trend. The MANFC-AT algorithm adaptively adjusts the time interval between consecutive samples according to the evolution trend...
This paper proposes a novel framework, based on State Estimation, as a Network Management System approach in order to control the traffic flow, routing, hardware malfunctioning, congestion and resource management in Data Communication Networks. Our proposed approach is aimed at eliminating anomalies and other discrepancies between network system models that typically lead to poor network performance...
Obtaining current traffic matrices is essential to traffic engineering (TE) methods. Because it is difficult to monitor traffic matrices, several methods for estimating them from link loads have been proposed. The models used in these methods, however, are incorrect for some real networks. Thus, methods improving the accuracy of estimation by changing routes also have been proposed. However, existing...
Multiple target tracking within a monitored field usually focuses on tracking the trajectories of each individual target. However, it is incapable of identifying and locating each target when the amount of targets is large or multiple targets are closely distributed. Based on above consideration, this paper proposes a novel problem of tracking a group target, where a group target is a set of targets...
The multi-access scheme of 802.11 wireless networks imposes difficulties in achieving predictable service quality in multi-hop networks. In such networks, the residual capacity of wireless links should be estimated for resource allocation services such as flow admission control. In this paper, we propose an accurate and non-intrusive method to estimate the residual bandwidth of an 802.11 link. Inputs...
Packet losses are a critical metric for network performance assessment. In this paper we present a novel methodology to accurately estimate the packet loss ratio in realtime in a fully distributed scenario. The constraint such systems must face is the large amount of resources required for keeping live performance assessment. Our contribution has two main parts. On the one hand we study the behaviour...
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