66 research outputs found

    MOON: a New Overlay Network Architecture for Mobility and QoS Support

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    The continuously increasing diffusion of mobile devices such as laptops, PDAs and smartphones, all equipped with enhanced functionalities, has led to numerous studies about mobility and to the definition of new network architectures capable to support it. Problems related to mobility have been addressed mostly operating on the network or transport layers of the Internet protocol stack. As a result, most of these solutions generally require modifying the TCP and/or the IP protocol. Although this approach is well suited to handle mobility, it lacks in compatibility with the Internet Protocol Suite. This consideration led us to study a fully TCP compatible and flexible approach we dubbed MOON, for MObile Overlay Network. This network architecture is currently under design at LIPAR, the Internet, Protocols and Network Architecture Lab of Politecnico di Torino

    A Survey of Different Dos Attacks on Wireless Network

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    Wireless technologies like Wireless LAN (WLAN) 802.11 picking up ubiquity in all associations, undertakings and colleges because of its profitability, cost sparing when contrasted with wired system and usability by enabling the system clients to move physically while keeping up an association with the wireless system. Wireless systems are main stream among the Laptop client group today in light of the portability and usability. Individuals working through remote association must know about the surroundings because of the different sorts of assaults made by the interlopers. Remote systems are extremely defenseless against (Denial of Service) DoS attacks. DoS attacks are an endeavor to make a machine or system asset inaccessible to its clients. It can happen in numerous layers of OSI demonstrate and can happen in different frame Network clients can ensure their frameworks with Wi-Fi Protected Access (WPA) security conventions and Wired Equivalent Privacy (WEP), however DoS attack still can't be averted utilizing these conventions. These attacks bring about debasement of the system quality or finish loss of accessibility of the system inside the association. This survey paper makes a review on various kinds of DoS attacks and their countermeasures on the framework systems which depend on the Access Points (AP). The fundamental assaults called Deauthentication and Disassociation Flooding. DoS assaults are considered there avoidance/discovery arrangements. Keywords- Access Points, DoS, Wireless Security, 802.11, Disassociation, Deauthentication, Flooding attack

    Wireless Network Security and Interworking

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    Cooperation Between Stations in Wireless Networks

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    In a wireless network, mobile nodes (MNs) repeatedly perform tasks such as layer 2 (L2) handoff, layer 3 (L3) handoff and authentication. These tasks are critical, particularly for real-time applications such as VoIP. We propose a novel approach, namely Cooperative Roaming (CR), in which MNs can collaborate with each other and share useful information about the network in which they move. We show how we can achieve seamless L2 and L3 handoffs regardless of the authentication mechanism used and without any changes to either the infrastructure or the protocol. In particular, we provide a working implementation of CR and show how, with CR, MNs can achieve a total L2+L3 handoff time of less than 16 ms in an open network and of about 21 ms in an IEEE 802.11i network. We consider behaviors typical of IEEE 802.11 networks, although many of the concepts and problems addressed here apply to any kind of mobile network

    Security and Privacy Issues in Wireless Mesh Networks: A Survey

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    This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

    Design and initial deployment of the wireless local area networking infrastructure at Sandia National Laboratories.

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    Patterns in network security: an analysis of architectural complexity in securing recursive inter-network architecture networks

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    Recursive Inter-Network Architecture (RINA) networks have a shorter protocol stack than the current architecture (the Internet) and rely instead upon separation of mech- anism from policy and recursive deployment to achieve large scale networks. Due to this smaller protocol stack, fewer networking mechanisms, security or otherwise, should be needed to secure RINA networks. This thesis examines the security proto- cols included in the Internet Protocol Suite that are commonly deployed on existing networks and shows that because of the design principles of the current architecture, these protocols are forced to include many redundant non-security mechanisms and that as a consequence, RINA networks can deliver the same security services with substantially less complexity

    Security and mobility in 802.11 structured networks

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    Mestrado em Engenharia Electrónica e TelecomunicaçõesNesta tese é apresentado um protocolo que permite handovers rápidos e seguros em redes estruturadas 802.11. Este protocolo recupera o paradigma original do 802.11: autenticar primeiro, reassociar depois. Partindo deste paradigma, apresentamos duas novas operações 802.11 de autenticação e (re)associacão, que permitem que uma estacão móvel realize reautenticacões e reassociações com as mesmas funcionalidades do 802.1X. Esta nova aproxiamação requer pouca mudança na arquitectura da rede, nomeadamente só necessita de um novo Servidor de Reautenticação, para armazenar os dados usados pelas estações móveis durante as reautenticações. Nesta tese é também apresentada uma extensão do nosso protocolo, de maneira a permitir uma migração rápida e segura entre ESS usando Mobile IP. ABSTRACT: This thesis presents a fast, secure handover protocol that recovers the original 802.11 paradigm: authenticate first, reassociate next. Following this paradigm, we present two new 802.11 authentication and (re)association operations which allow a mobile station to perform network reauthentications and reassociations with the same functionality of a complete 802.1X authentication. This new approach requires very little from the environment, namely it only requires a new, central network Reauthentication Service, for storing data used in the reauthentication of stations. This thesis also presents a layer 3 extension of our protocol, to support fast, secure transitions between ESS using Mobile IP

    Multi-layer traffic control for wireless networks

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    Le reti Wireless LAN, così come definite dallo standard IEEE 802.11, garantiscono connettività senza fili nei cosiddetti “hot-spot” (aeroporti, hotel, etc.), nei campus universitari, nelle intranet aziendali e nelle abitazioni. In tali scenari, le WLAN sono denotate come “ad infrastruttura” nel senso che la copertura della rete è basata sulla presenza di un “Access Point” che fornisce alle stazioni mobili l’accesso alla rete cablata. Esiste un ulteriore approccio (chiamato “ad-hoc”) in cui le stazioni mobili appartenenti alla WLAN comunicano tra di loro senza l’ausilio dell’Access Point. Le Wireless LAN tipicamente sono connesse alla rete di trasporto (che essa sia Internet o una Intranet aziendale) usando un’infrastruttura cablata. Le reti wireless Mesh ad infrastruttura (WIMN) rappresentano un’alternativa valida e meno costosa alla classica infrastruttura cablata. A testimonianza di quanto appena affermato vi è la comparsa e la crescita sul mercato di diverse aziende specializzate nella fornitura di infrastrutture di trasporto wireless e il lancio di varie attività di standardizzazione (tra cui spicca il gruppo 802.11s). La facilità di utilizzo, di messa in opera di una rete wireless e i costi veramente ridotti hanno rappresentato fattori critici per lo straordinario successo di tale tecnologia. Di conseguenza possiamo affermare che la tecnologia wireless ha modificato lo stile di vita degli utenti, il modo di lavorare, il modo di passare il tempo libero (video conferenze, scambio foto, condivisione di brani musicali, giochi in rete, messaggistica istantanea ecc.). D’altro canto, lo sforzo per garantire lo sviluppo di reti capaci di supportare servizi dati ubiqui a velocità di trasferimento elevate è strettamente legato a numerose sfide tecniche tra cui: il supporto per l’handover tra differenti tecnologie (WLAN/3G), la certezza di accesso e autenticazione sicure, la fatturazione e l’accounting unificati, la garanzia di QoS ecc. L’attività di ricerca svolta nell’arco del Dottorato si è focalizzata sulla definizione di meccanismi multi-layer per il controllo del traffico in reti wireless. In particolare, nuove soluzioni di controllo del traffico sono state realizzate a differenti livelli della pila protocollare (dallo strato data-link allo strato applicativo) in modo da fornire: funzionalità avanzate (autenticazione sicura, differenziazione di servizio, handover trasparente) e livelli soddisfacenti di Qualità del Servizio. La maggior parte delle soluzioni proposte in questo lavoro di tesi sono state implementate in test-bed reali. Questo lavoro riporta i risultati della mia attività di ricerca ed è organizzato nel seguente modo: ogni capitolo presenta, ad uno specifico strato della pila protocollare, un meccanismo di controllo del traffico con l’obiettivo di risolvere le problematiche presentate precedentemente. I Capitoli 1 e 2 fanno riferimento allo strato di Trasporto ed investigano il problema del mantenimento della fairness per le connessioni TCP. L’unfairness TCP conduce ad una significativa degradazione delle performance implicando livelli non soddisfacenti di QoS. Questi capitoli descrivono l’attività di ricerca in cui ho impiegato il maggior impegno durante gli studi del dottorato. Nel capitolo 1 viene presentato uno studio simulativo delle problematiche di unfairness TCP e vengono introdotti due possibili soluzioni basate su rate-control. Nel Capitolo 2 viene derivato un modello analitico per la fairness TCP e si propone uno strumento per la personalizzazione delle politiche di fairness. Il capitolo 3 si focalizza sullo strato Applicativo e riporta diverse soluzioni di controllo del traffico in grado di garantire autenticazione sicura in scenari di roaming tra provider wireless. Queste soluzioni rappresentano parte integrante del framework UniWireless, un testbed nazionale sviluppato nell’ambito del progetto TWELVE. Il capitolo 4 descrive, nuovamente a strato Applicativo, una soluzione (basata su SIP) per la gestione della mobilità degli utenti in scenari di rete eterogenei ovvero quando diverse tecnologie di accesso radio sono presenti (802.11/WiFi, Bluetooth, 2.5G/3G). Infine il Capitolo 5 fa riferimento allo strato Data-Link presentando uno studio preliminare di un approccio per il routing e il load-balancing in reti Mesh infrastrutturate.Wireless LANs, as they have been defined by the IEEE 802.11 standard, are shared media enabling connectivity in the so-called “hot-spots” (airports, hotel lounges, etc.), university campuses, enterprise intranets, as well as “in-home” for home internet access. With reference to the above scenarios, WLANs are commonly denoted as “infra-structured” in the sense that WLAN coverage is based on “Access Points” which provide the mobile stations with access to the wired network. In addition to this approach, there exists also an “ad-hoc” mode to organize WLANs where mobile stations talk to each other without the need of Access Points. Wireless LANs are typically connected to the wired backbones (Internet or corporate intranets) using a wired infrastructure. Wireless Infrastructure Mesh Networks (WIMN) may represent a viable and cost-effective alternative to this traditional wired approach. This is witnessed by the emergence and growth of many companies specialized in the provisioning of wireless infrastructure solutions, as well as the launch of standardization activities (such as 802.11s). The easiness of deploying and using a wireless network, and the low deployment costs have been critical factors in the extraordinary success of such technology. As a logical consequence, the wireless technology has allowed end users being connected everywhere – every time and it has changed several things in people’s lifestyle, such as the way people work, or how they live their leisure time (videoconferencing, instant photo or music sharing, network gaming, etc.). On the other side, the effort to develop networks capable of supporting ubiquitous data services with very high data rates in strategic locations is linked with many technical challenges including seamless vertical handovers across WLAN and 3G radio technologies, security, 3G-based authentication, unified accounting and billing, consistent QoS and service provisioning, etc. My PhD research activity have been focused on multi-layer traffic control for Wireless LANs. In particular, specific new traffic control solutions have been designed at different layers of the protocol stack (from the link layer to the application layer) in order to guarantee i) advanced features (secure authentication, service differentiation, seamless handover) and ii) satisfactory level of perceived QoS. Most of the proposed solutions have been also implemented in real testbeds. This dissertation presents the results of my research activity and is organized as follows: each Chapter presents, at a specific layer of the protocol stack, a traffic control mechanism in order to address the introduced above issues. Chapter 1 and Charter 2 refer to the Transport Layer, and they investigate the problem of maintaining fairness for TCP connections. TCP unfairness may result in significant degradation of performance leading to users perceiving unsatisfactory Quality of Service. These Chapters describe the research activity in which I spent the most significant effort. Chapter 1 proposes a simulative study of the TCP fairness issues and two different solutions based on Rate Control mechanism. Chapter 2 illustrates an analytical model of the TCP fairness and derives a framework allowing wireless network providers to customize fairness policies. Chapter 3 focuses on the Application Layer and it presents new traffic control solutions able to guarantee secure authentication in wireless inter-provider roaming scenarios. These solutions are an integral part of the UniWireless framework, a nationwide distributed Open Access testbed that has been jointly realized by different research units within the TWELVE national project. Chapter 4 describes again an Application Layer solution, based on Session Initiation Protocol to manage user mobility and provide seamless mobile multimedia services in a heterogeneous scenario where different radio access technologies are used (802.11/WiFi, Bluetooth, 2.5G/3G networks). Finally Chapter 5 refers to the Data Link Layer and presents a preliminary study of a general approach for routing and load balancing in Wireless Infrastructure Mesh Network. The key idea is to dynamically select routes among a set of slowly changing alternative network paths, where paths are created through the reuse of classical 802.1Q multiple spanning tree mechanisms
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