62 research outputs found

    SRLG: To Finding the Packet Loss in Peer to Peer Network

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    We introduce the ideas of watching methods (MPs) and watching cycles (MCs) for distinctive localization of shared risk connected cluster (SRLG) failures in all-optical networks. An SRLG failure causes multiple links to interrupt at the same time due to the failure of a typical resource. MCs (MPs) begin and finish at identical (distinct) watching location(s).They are constructed such any SRLG failure leads to the failure of a unique combination of methods and cycles. We tend to derive necessary and ample conditions on the set of MCs and MPs required for localizing associate single SRLG failure in a capricious graph. We determine the minimum range of optical splitters that area unit needed to watch all SRLG failures within the network. Extensive simulations area unit won�t to demonstrate the effectiveness of the planned watching technique

    On Signaling-Free Failure Dependent Restoration in All-Optical Mesh Networks

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    Failure dependent protection (FDP) is known to achieve optimal capacity efficiency among all types of protection, at the expense of longer recovery time and more complicated signaling overhead. This particularly hinders the usage of FDP in all-optical mesh networks. As a remedy, the paper investigates a new restoration framework that enables all-optical fault management and device configuration via state-of-the-art failure localization techniques, such that the FDP restoration process. It can be implemented without relying on any control plane signaling. With the proposed restoration framework, a novel spare capacity allocation problem is defined, and is further analyzed on circulant topologies for any single link failure, aiming to gain a solid understanding of the problem. By allowing reuse of monitoring resources for restoration capacity, we are particularly interested in the monitoring resource hidden property where less or even no monitoring resources are consumed as more working traffic is in place. To deal with general topologies, we introduce a novel heuristic approach to the proposed spare capacity allocation problem, which comprises a generic FDP survivable routing scheme followed by a novel monitoring resource allocation method. Extensive simulation is conducted to examine the proposed scheme and verify the proposed restoration framework

    Fast emergency paths schema to overcome transient link failures in ospf routing

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    A reliable network infrastructure must be able to sustain traffic flows, even when a failure occurs and changes the network topology. During the occurrence of a failure, routing protocols, like OSPF, take from hundreds of milliseconds to various seconds in order to converge. During this convergence period, packets might traverse a longer path or even a loop. An even worse transient behaviour is that packets are dropped even though destinations are reachable. In this context, this paper describes a proactive fast rerouting approach, named Fast Emergency Paths Schema (FEP-S), to overcome problems originating from transient link failures in OSPF routing. Extensive experiments were done using several network topologies with different dimensionality degrees. Results show that the recovery paths, obtained by FEPS, are shorter than those from other rerouting approaches and can improve the network reliability by reducing the packet loss rate during the routing protocols convergence caused by a failure.Comment: 18 page

    Fault Localization in All-Optical Mesh Networks

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    Fault management is a challenging task in all-optical wavelength division multiplexing (WDM) networks. However, fast fault localization for shared risk link groups (SRLGs) with multiple links is essential for building a fully survival and functional transparent all-optical mesh network. Monitoring trail (m-trail) technology is an effective approach to achieve the goal, whereby a set of m-trails are derived for unambiguous fault localization (UFL). However, an m-trail traverses through a link by utilizing a dedicated wavelength channel (WL), causing a significant amount of resource consumption. In addition, existing m-trail methods incur long and variable alarm dissemination delay. We introduce a novel framework of real-time fault localization in all-optical WDM mesh networks, called the monitoring-burst (m-burst), which aims at initiating a balanced trade-off between consumed monitoring resources and fault localization latency. The m-burst framework has a single monitoring node (MN) and requires one WL in each unidirectional link if the link is traversed by any m-trail. The MN launches short duration optical bursts periodically along each m-trail to probe the links of the m-trail. Bursts along different m-trails are kept non-overlapping through each unidirectional link by scheduling burst launching times from the MN and multiplexing multiple bursts, if any, traversing the link. Thus, the MN can unambiguously localize the failed links by identifying the lost bursts without incurring any alarm dissemination delay. We have proposed several novel m-trail allocation, burst launching time scheduling, and node switch fabric configuration schemes. Numerical results show that the schemes, when deployed in the m-burst framework, are able to localize single-link and multi-link SRLG faults unambiguously, with reasonable fault localization latency, by using at most one WL in each unidirectional link. To reduce the fault localization latency further, we also introduce a novel methodology called nested m-trails. At first, mesh networks are decomposed into cycles and trails. Each cycle (trail) is realized as an independent virtual ring (linear) network using a separate pair of WLs (one WL in each direction) in each undirected link traversed by the cycle (trail). Then, sets of m-trails, i.e., nested m-trails, derived in each virtual network are deployed independently in the m-burst framework for ring (linear) networks. As a result, the fault localization latency is reduced significantly. Moreover, the application of nested m-trails in adaptive probing also reduces the number of sequential probes significantly. Therefore, practical deployment of adaptive probing is now possible. However, the WL consumption of the nested m-trail technique is not limited by one WL per unidirectional link. Thus, further investigation is needed to reduce the WL consumption of the technique.1 yea

    Reliable networks design and modeling (foreword)

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    Force and Proficient Data Replica Discovery in WSN

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    We propose the distributed clone detection method and star topology is used to discover the replica data in the wireless sensor networks. In this paper vitality practiced space careful clone guarantee prosperous clone assault location and carry on satisfactory system period of time. Solidly, we tend to abuse the realm information of sensors and subjectively separate witnesses located in an exceedingly ring region to envision the genuineness of sensors and to report known clone assaults. Besides the clone detection likelihood, we tend to additionally contemplate energy consumption and memory storage within the style of clone detection protocol, i.e., associate degree energy- and memory economical distributed clone detection protocol with random witness choice theme in WSNs

    Signaling Free Localization of Node Failures in All-Optical Networks

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