13,456 research outputs found

    Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results

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    Fixed and mobile telecom operators, enterprise network operators and cloud providers strive to face the challenging demands coming from the evolution of IP networks (e.g. huge bandwidth requirements, integration of billions of devices and millions of services in the cloud). Proposed in the early 2010s, Segment Routing (SR) architecture helps face these challenging demands, and it is currently being adopted and deployed. SR architecture is based on the concept of source routing and has interesting scalability properties, as it dramatically reduces the amount of state information to be configured in the core nodes to support complex services. SR architecture was first implemented with the MPLS dataplane and then, quite recently, with the IPv6 dataplane (SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering of packets across nodes to a general network programming approach, making it very suitable for use cases such as Service Function Chaining and Network Function Virtualization. In this paper we present a tutorial and a comprehensive survey on SR technology, analyzing standardization efforts, patents, research activities and implementation results. We start with an introduction on the motivations for Segment Routing and an overview of its evolution and standardization. Then, we provide a tutorial on Segment Routing technology, with a focus on the novel SRv6 solution. We discuss the standardization efforts and the patents providing details on the most important documents and mentioning other ongoing activities. We then thoroughly analyze research activities according to a taxonomy. We have identified 8 main categories during our analysis of the current state of play: Monitoring, Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL

    On Diagnosis of Forwarding Plane via Static Forwarding Rules in Software Defined Networks

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    Software Defined Networks (SDN) decouple the forwarding and control planes from each other. The control plane is assumed to have a global knowledge of the underlying physical and/or logical network topology so that it can monitor, abstract and control the forwarding plane. In our paper, we present solutions that install an optimal or near-optimal (i.e., within 14% of the optimal) number of static forwarding rules on switches/routers so that any controller can verify the topology connectivity and detect/locate link failures at data plane speeds without relying on state updates from other controllers. Our upper bounds on performance indicate that sub-second link failure localization is possible even at data-center scale networks. For networks with hundreds or few thousand links, tens of milliseconds of latency is achievable.Comment: Submitted to Infocom'14, 9 page

    Optical layer monitoring schemes for fast link failure localization in all-optical networks

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    Optical layer monitoring and fault localization serves as a critical functional module in the control and management of optical networks. An efficient monitoring scheme aims at minimizing not only the hardware cost required for 100{%} link failure localization, but also the number of redundant alarms and monitors such that the network fault management can be simplified as well. In recent years, several optical layer monitoring schemes were reported for fast and efficient link failure localization, including simple, non-simple monitoring cycle (m-cycle) and monitoring trail (m-trail). Optimal ILP (Integer Linear Program) models and heuristics were also proposed with smart design philosophy on flexibly trading off different objectives. This article summarizes those innovative ideas and methodologies with in-depth analysis on their pros and cons. We also provide insights on future research topics in this area, as well as possible ways for extending the new failure localization approaches to other network applications. © 2005 IEEE.published_or_final_versio

    Super monitor design for fast link failure localization in all-optical networks

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    Monitoring cycle (m-cycle) based design is cost efficient for fast link failure detection and localization in all-optical networks. An m-cycle is an optical loop-back pre-cross-connection of a supervisory wavelength with a dedicated monitor. Generally, a simple monitor is placed at an arbitrary node of an m-cycle for supervision. In this paper, we propose a novel monitor structure, called super monitor. A super monitor is used to supervise multiple intersecting cycles and placed at the intersection node. For a given set of m-cycles, we use super monitors to replace some (or all) simple monitors that originally locate in the set. Two major advantages of the super monitor are: 1) it has lower hardware cost; 2) the collocation of monitoring devices reduces the management cost simultaneously. Besides, the super monitor does not incur additional bandwidth cost. We formulate an integer linear program (ILP) to solve the problem of monitor placement. Numerical results show that our ILP can efficiently place the monitors with a significantly minimized monitoring cost. © 2011 IEEE.published_or_final_versionThe 2011 IEEE International Conference on Communications (ICC 2011), Kyoto, Japan, 5-9 June 2011. In Proceedings of the IEEE ICC, 2011, p. 1-

    A Novel Framework of Fast and Unambiguous Link Failure Localization via Monitoring Trails

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    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

    Sensor Node Failure Detection Using Round Trip Path in WSNs

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    Now a days, applications of wireless sensor networks (WSNs) has been increased due to its vast potential to connect the physical world to the practical world. Also, advancement in microelectronic fabrication technology reduced the cost of manufacturing convenient wireless sensor nodes and now it becomes a trend to deploy the large numbers of wireless sensors in WSNs so that to increase the quality of service (QoS). The QoS of such WSNs is mainly affected by the faulty or malfunctioning sensor nodes. Probability of sensor node failure increases if number of sensor node increases in the network. For maintaining the better QoS under failure conditions such faulty sensor node should be detected and it should be removed. In this proposed method, faulty sensor node is detected by calculating the round trip delay (RTD) time of round trip paths and comparing them with threshold value. This proposed method is tested with three sensors Nodes designed using microcontroller, sensor and ZigBee. The main server section which will display the failure sensor node is also designed using microcontroller and ZigBee
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