Vasilios A. Siris

A Survey of Information-Centric Networking Research

The current Internet architecture was founded upon a host-centric communication model, which was appropriate for coping with the needs of the early Internet users. Internet usage has evolved however, with most users mainly interested in accessing (vast amounts of) information, irrespective of its physical location. This paradigm shift in the usage model of the Internet, along with the pressing needs for, among others, better security and mobility support, has led researchers into considering a radical change to the Internet architecture. In this direction, we have witnessed many research efforts investigating Information-Centric Networking (ICN) as a foundation upon which the Future Internet can be built. Our main aims in this survey are: (a) to identify the core functionalities of ICN architectures, (b) to describe the key ICN proposals in a tutorial manner, highlighting the similarities and differences among them with respect to those core functionalities, and (c) to identify the key weaknesses of ICN proposals and to outline the main unresolved research challenges in this area of networking research.

Application of anomaly detection algorithms for detecting SYN flooding attacks

We investigate statistical anomaly detection algorithms for detecting SYN flooding, which is the most common type of denial of service (DoS) attack. The two algorithms considered are an adaptive threshold algorithm and a particular application of the cumulative sum (CUSUM) algorithm for change point detection. The performance is investigated in terms of the detection probability, the false alarm ratio, and the detection delay. Particular emphasis is on investigating the tradeoffs among these metrics and how they are affected by the parameters of the algorithm and the characteristics of the attacks. Such an investigation can provide guidelines to effectively tune the parameters of the detection algorithm to achieve specific performance requirements in terms of the above metrics.

A Contention-Aware Routing Metric for Multi-Rate Multi-Radio Mesh Networks

We present a new routing metric for multi-rate multi-radio mesh networks, which takes into account both contention for the shared wireless channel and rate diversity in multi-radio multi-channel mesh networks. A key property of the proposed contention-aware transmission time (CATT) metric is that it is isotonic, hence can be applied to link-state routing protocols. We have implemented the CATT metric in the OLSR routing protocol, and evaluate it in a test-bed with mesh nodes each equipped with four radio interfaces. Our experiments show that the proposed routing metric significantly outperforms other metrics that have appeared in the literature, in a number of scenarios that correspond to different mesh network topologies.

Resource control for elastic traffic in CDMA networks

We present a framework for resource control in CDMA networks carrying elastic traffic, considering both the uplink and the downlink direction. The framework is based on microeconomics and congestion pricing, and seeks to exploit the joint control of the transmission rate and the signal quality in order to achieve efficient utilization of network resources, in a distributed and decentralized manner. An important feature of the framework is that it incorporates both the congestion for shared resources in wireless and wired networks, and the cost of battery power at mobile hosts. We prove that for elastic traffic, where users value only their average throughput, the users net utility maximization problem can be decomposed into two simpler problems: one involving the selection of the optimal signal quality, and one involving the selection of the optimal transmission rate. Based on this result, the selection of signal quality can be performed as done today using outer loop power control, while rate adaptation can be integrated with rate adaptation at the transport layer.

Caching and mobility support in a publish-subscribe internet architecture

The Internet is straining to meet demands that its design never anticipated, such as supporting billions of mobile devices and transporting huge amounts of multimedia content. The publish-subscribe Internet (PSI) architecture, a clean slate information-centric networking approach to the future Internet, was designed to satisfy the current and emerging user demands for pervasive content delivery, which the Internet can no longer handle. This article provides an overview of the PSI architecture, explaining its operation from bootstrapping to information delivery, focusing on its support for network layer caching and seamless mobility, which make PSI an excellent platform for ubiquitous information delivery.

Application of the many sources asymptotic and effective bandwidths to traffic engineering

Accurate yet simple methods for traffic engineering are important for efficient management of resources in broadband networks. The goal of this paper is to apply and evaluate large deviation techniques for traffic engineering. In particular, we employ the recently developed theory of effective bandwidths, where the effective bandwidth depends not only on the statistical characteristics of the traffic stream, but also on a link’s operating point through two parameters, the space and time parameters, which can be computed using the many sources asymptotic. We show that this effective bandwidth definition can accurately quantify resource usage. Furthermore, we estimate and interpret values of the space and time parameters for various mixes of real traffic demonstrating how these values can be used to clarify the effects on the link performance of the time scales of traffic burstiness, of the link resources (capacity and buffer), and of traffic control mechanisms such as traffic shaping. Our experiments involve a large set of MPEG‐1 compressed video and Internet Wide Area Network (WAN) traces, as well as modeled voice traffic.

A study of simple usage-based charging schemes for broadband networks

Operators of multi‐service networks require simple charging schemes with which they can fairly recover costs from their users and effectively allocate network resources. This paper studies an approach for computing such charges from simple measurements (time and volume), and relating these to bounds of the effective bandwidth. To achieve economic efficiency, it is necessary that usage‐based charging schemes capture the relative amount of resources used by connections. Based on this criteria, we evaluate our approach for real traffic consisting of Internet Wide Area Network traces and MPEG‐1 compressed video. Its incentive compatibility is shown with an example involving deterministic multiplexing, and the effect of pricing on a networks equilibrium is investigated for deterministic and statistical multiplexing. Finally, we investigate the incentives for traffic shaping provided by the approach.

Optimal CWmin selection for achieving proportional fairness in multi-rate 802.11e WLANs: test-bed implementation and evaluation

We investigate the optimal selection of minimum contention window values to achieve proportional fairness in a multirate IEEE 802.11e test-bed. Unlike other approaches, the proposed model accounts for the contention-based nature of 802.11s MAC layer operation and considers the case where stations can have different weights corresponding to different throughput classes. Our test-bed evaluation considers both the long-term throughput achieved by wireless stations and the short-term fairness. When all stations have the same transmission rate, optimality is achieved when a stations throughput is proportional to its weight factor, and the optimal minimum contention windows also maximize the aggregate throughput. When stations have different transmission rates, the optimal minimum contention window for high rate stations is smaller than for low rate stations. Furthermore, we compare proportional fairness with time-based fairness, which can be achieved by adjusting packet sizes so that low and high rate stations have equal successful transmission times, or by adjusting the transmission opportunity (TXOP)limit so that high rate stations transmit multiple back-to-back packets and thus occupy the channel for the same time as low rate stations that transmit a single packet. The test-bed experiments show that when stations have different transmission rates and the same weight, proportional fairness achieves higher performance than the time-based fairness approaches, in terms of both aggregate utility and throughput.

Managing and pricing service level agreements for differentiated services

We present an approach to managing and pricing service level agreements (SLA) for differentiated services that uses a simple upper bound for the effective bandwidth of the conforming traffic as a proxy for resource usage. The bound depends on the users traffic profile (peak rate and token bucket descriptor). Usage charges for a specific time period are proportional to this proxy, and their calculation requires only measurements of volume. We discuss and present experimental results regarding the incentives and fairness of the proxy, which is required in order to achieve economic efficiency. An important feature of our approach is the simplicity of the users procedure for selecting optimal token bucket parameters. Our approach is quite generic and can be applied to scheduling disciplines that enable the provision of multiple service classes with different levels of performance. Finally, we present a case study for two service classes, real-time and non-real-time, with actual Internet traces.

Proactive selective neighbor caching for enhancing mobility support in information-centric networks

We present a Selective Neighbor Caching (SNC) approach for enhancing seamless mobility in ICN architectures. The approach is based on proactively caching information requests and the corresponding items to a subset of proxies that are one hop away from the proxy a mobile is currently connected to. A key contribution of this paper is the definition of a target cost function that captures the tradeoff between delay and cache cost, and a simple procedure for selecting the appropriate subset of neighbors which considers the mobility behavior of users. We present investigations for the steady-state and transient performance of the proposed scheme which identify and quantify its gains compared to proactively caching in all neighbor proxies and to the case where no caching is performed. Moreover, our investigations show how these gains are affected by the delay and cache cost, and the mobility behavior.