1,721,012 research outputs found
Quality of Service Routing of Bandwidth Guaranteed Connections in MPLS Networks
No full textFinding a path in the network for a new incoming connection able to guarantee some quality parameters such as bandwidth and delay is the task of QoS routing techniques developed for new IP networks based on label forwarding. In this paper we focus on the routing of bandwidth guaranteed flows in a dynamic scenario where connection requests arrive at the network edge nodes. When more than a path satisfying the bandwidth demand exists, the selection of the path is done in order to minimize the blocking probability of future requests. We propose a new routing algorithm named Virtual Flow Deviation which exploits the information of the ingress and egress nodes of the network and the traffic statistics. We show that this new algorithm allows to reduce remarkably the blocking probability in most scenarios with respect to previously proposed schemes
DSA-Mesh: a Distributed Security Architecture for Wireless Mesh Networks
No full textWireless mesh networks (WMNs) have emerged recently as a technology for next-generation wireless networking.
They consist of mesh routers and clients, where mesh routers are almost static and form the backbone of WMNs.
WMNs provide network access for both mesh and conventional clients.
In this paper, we propose DSA-Mesh, a fully distributed security architecture that provides access control for
mesh routers as well as a key distribution scheme that supports layer-2 encryption to ensure security and data
confidentiality of all communications that occur in the backbone of the WMN.
DSA-Mesh exploits the routing capabilities of mesh routers: after connecting to the access network as generic
wireless clients, new mesh routers authenticate to a key management service (consisting of several servers)
implemented using threshold cryptography, and obtain a temporary key that is used both to prove their credentials
to neighbor nodes and to encrypt all the traffic transmitted on the wireless backbone links.
A key feature in the design of DSA-Mesh is its independence from the underlying wireless technology used by
network nodes to form the backbone. Furthermore, DSA-Mesh allows seamless mobility of mesh routers. Since
it is completely distributed, DSA-Mesh permits to deploy automatically and incrementally large wireless mesh
networks, while increasing, at the same time, the robustness of the system by eliminating the single point of failure
typical of centralized architectures.
DSA-Mesh has been implemented in Network Simulator, and extensive simulations have been performed in largescale
network scenarios, comparing it to a static key approach and to a centralized architecture where a single key
server is deployed.
Numerical results show that our proposed architecture considerably increases the WMN security, with a negligible
impact on the network performance, thus representing an effective solution for wireless mesh networking
Metodo di Allocazione di Banda, di Tipo Distribuito, in una Rete Passiva con un Accesso Multiplo CSMA/CD
No full textMetodo di allocazione di una banda prefissata tra una pluralità di terminali (ONU) connessi ad un concentratore (HUB) in una rete con un accesso multiplo CSMA/CD caratterizzato dal fatto di comprendere le seguenti fasi: ogni terminale (ONU) presente in rete, ad intervalli di tempo prefissati, individua i terminali (ONU) attivi nel precedente intervallo di tempo; ogni terminale (ONU) attivo determina un valore di banda ad esso disponibile, mediante un metodo prefissato; ogni terminale (ONU) attivo si alloca detto valore di banda ad esso disponibile. In una prima forma di realizzazione si verifica quali ONU erano attive nel precedente intervallo di tempo, mediante l’ascolto del traffico upstream riflesso indietro a tutte le ONU dal HUB passivo. La banda in upstream è distribuita tra tutte le ONU che erano attive nel precedente intervallo di tempo proporzionalmente al loro peso. In una seconda forma di realizzazione, si tiene conto dell’ammontare del traffico trasmesso dalle ONU attive nel precedente intervallo di tempo nel processo di allocazione della banda
Design and Implementation of MobiSEC: a Complete Security Architecture for Wireless Mesh Networks
No full textWireless mesh networks (WMNs) have emerged recently as a technology for next-generation wireless networking. They consist of mesh routers and clients, where mesh routers are almost static and form the backbone of WMNs. WMNs provide network access for both mesh and conventional clients.
In this paper we propose MobiSEC, a complete security architecture that provides both access control for mesh users and routers as well as a key distribution scheme that supports layer-2 encryption to ensure security and data confidentiality of all communications that occur in the WMN.
MobiSEC extends the IEEE 802.11i standard exploiting the routing capabilities of mesh routers; after connecting to the access network as generic wireless clients, new mesh routers authenticate to a central server and obtain a temporary key that is used both to prove their credentials to neighbor nodes and to encrypt all the traffic transmitted on the wireless backbone links.
A key feature in the design of MobiSEC is its independence from the underlying wireless technology used by network nodes to form the backbone. Furthermore, MobiSEC allows seamless mobility of both mesh clients and routers.
MobiSEC has been implemented and integrated in MobiMESH, a WMN implementation that provides a complete framework for testing and analyzing the behavior of a mesh network in real-life environments. Moreover, extensive simulations have been performed in large-scale network scenarios using Network Simulator.
Numerical results show that our proposed architecture considerably increases the WMN security, with a negligible impact on the network performance, thus representing an effective solution for wireless mesh networking
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