341 research outputs found

    A Highly-Available Multiple Region Multi-access Edge Computing Platform with Traffic Failover

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    One of the main challenges in the Multi-access Edge Computing (MEC) is steering traffic from clients to the nearest MEC instances. If the nearest MEC fails, a failover mechanism should provide mitigation by steering the traffic to the next nearest MEC. There are two conventional approaches to solve this problem, i.e., GeoDNS and Internet Protocol (IP) anycast. GeoDNS is not failover friendly because of the Domain Name System (DNS) cache lifetime. Moreover, the use of a recursive resolver may inaccurately translate the IP address to its geolocation. Thus, this thesis studies and proposes a highly available MEC platform leveraging IP anycast. We built a proof-of-concept using Kubernetes, MetalLB, and a custom health-checker running on the GNS3 network emulator. We measured latency, failure percentage, and Mean Time To Repair (MTTR) to observe the system's behavior. The performance evaluation of the proposed solution shows an average recovery time better than one second. The number of failed requests and latency overhead grows linearly as the failover time and latency between two MECs increases. This thesis demonstrates the effectiveness of IP anycast for MEC applications to steer the traffic to the nearest MEC instance and to enhance resiliency with minor overhead

    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

    An SDN-based Overlay Networking Solution for Transparent Multi-homed Vehicular Communications

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    This dissertation consists in the design and development of an Overlay Network for vehicular applications using the SDN paradigm, capable of supporting seamless handover and load balancing between multiple Vehicle-to-Infrastructure (V2I) networks, and also seamless handover of users' terminals between different vehicle zones, such as train carriages. The main contributions of this work are threefold: 1) the overlay SDN-based network architecture designed for vehicular applications such as trains, contemplating the support for multiple V2I operators and multiple gateways per vehicle (e.g., one per carriage); 2) the SDN orchestration component that implements the handover (performed by a User Terminal) from one carriage to another, without Internet connection interruption; and 3) the SDN orchestration component that implements the load-balancing of traffic over multiple V2I links that connect each carriage to the Internet, optimizing the utilization of available network resources and resulting QoS. All the features related to these contributions were implemented in a centralized SDN controller, which has a holistic view of the overlay network, which orchestrates the network hardware on-board of the vehicles. A Proof-of-Concept of the overlay network and the developed components was implemented using Virtual Machines emulating: the network elements of two carriages; the user terminals; a centralized orchestrator; an Internet gateway; and multiple V2I connections representing different operators. Different functional and performance tests were executed, targeting each component, which allowed to successfully validate each contribution

    Rationale, Scenarios, and Profiles for the Application of the Internet Protocol Suite (IPS) in Space Operations

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    This greenbook captures some of the current, planned and possible future uses of the Internet Protocol (IP) as part of Space Operations. It attempts to describe how the Internet Protocol is used in specific scenarios. Of primary focus is low-earth-orbit space operations, which is referred to here as the design reference mission (DRM). This is because most of the program experience drawn upon derives from this type of mission. Application profiles are provided. This includes parameter settings programs have proposed for sending IP datagrams over CCSDS links, the minimal subsets and features of the IP protocol suite and applications expected for interoperability between projects, and the configuration, operations and maintenance of these IP functions. Of special interest is capturing the lessons learned from the Constellation Program in this area, since that program included a fairly ambitious use of the Internet Protocol

    Connection robustness for wireless moving networks using transport layer multi-homing

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    Given any form of mobility management through wireless communication, one useful enhancement is improving the reliability and robustness of transport-layer connections in a heterogeneous mobile environment. This is particularly true in the case of mobile networks with multiple vertical handovers. In this thesis, issues and challenges in mobility management for mobile terminals in such a scenario are addressed, and a number of techniques to facilitate and improve efficiency and the QoS for such a handover are proposed and investigated. These are initially considered in an end-to-end context and all protocols and changes happened in the middleware of the connection where the network is involved with handover issues and end user transparency is satisfied. This thesis begins by investigating mobility management solutions particularly the transport layer models, also making significant observation pertinent to multi-homing for moving networks in general. A new scheme for transport layer tunnelling based on SCTP is proposed. Consequently a novel protocol to handle seamless network mobility in heterogeneous mobile networks, named nSCTP, is proposed. Efficiency of this protocol in relation to QoS for handover parameters in an end-to-end connection while wired and wireless networks are available is considered. Analytically and experimentally it has been proved that this new scheme can significantly increase the throughput, particularly when the mobile networks roam frequently. The detailed plan for the future improvements and expansion is also provided.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    An Architecture for Reliable Encapsulation Endpoints using Commodity Hardware

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    Customized hardware is expensive and making software reliable is difficult to achieve as complexity increases. Recent trends towards computing in the cloud have highlighted the importance of being able to operate continuously in the presence of unreliable hardware and, as services continue to grow in complexity, it is necessary to build systems that are able to operate not only in the presence of unreliable hardware but also failure-vulnerable software. This thesis describes a newly developed approach for building networking software that exposes a reliable encapsulation service to clients and runs on unreliable, commodity hardware without substantially increasing the implementation complexity. The proposal was implemented in an existing encapsulation system, and experimental analysis has shown that packets are lost for between 200 ms and 1 second during a failover, and that a failover adds less than 5 seconds to the total download time of several sizes of files. The approach described in this thesis demonstrates the viability of building high availability systems using commodity components and failure-vulnerable server software

    OpenFlow-based Distributed and Fault-Tolerant Software Switch Architecture

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    We are living in the era where each of us is connected with each other virtually across the globe. We are sharing the information electronically over the internet every second of our day. There are many networking devices involved in sending the information over the internet. They are routers, gateways, switches, PCs, laptops, handheld devices, etc. The switches are very crucial elements in delivering packets to the intended recipients. Now the networking field is moving towards Software Defined Networking and the network elements are being slowly replaced by the software applications run by OpenFlow protocols. For example the switching functionality in local area networks could be achieved with software switches like OpenvSwitch (OVS), LINC-Switch, etc. Now a days the organizations depend on the datacenters to run their services. The application servers are being run from virtual machines on the hosts to better utilize the computing resources and make the system more scalable. The application servers need to be continuously available to run the business for which they are deployed for. Software switches are used to connect virtual machines as an alternative to Top of Rack switches. If such software switch fails then the application servers will not be able to connect to its clients. This may severely impact the business serviced by the application servers, deployed on the virtual machines. For reliable data connectivity, the switching elements need to be continuously functional. There is a need for reliable and robust switches to cater the today's networking infrastructure. In this study, the software switch LINC-Switch is implemented as distributed application on multiple nodes to make it resilient to failure. The fault-tolerance is achieved by using the distribution properties of the programming language Erlang. By implementing the switch on three redundant nodes and starting the application as a distributed application, the switch will be serving its purpose very promptly by restarting it on other node in case it fails on the current node by using failover/takeover mechanisms of Erlang. The tolerance to failure of the LINC-Switch is verified with Ping based experiment on the GENI test bed and on the Xen-cluster in our Lab.Engineering Technology, Department o

    Performance Evaluation of Multimedia Content Distribution over Multi-Homed Wireless Networks

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    ABSTRACT-The growing availability of IP based heterogeneous wireless access technologies coupled with the increasing capabilities of mobile devices is creating opportunities for multimedia distribution. Through its multi-homing feature, the ability to support multiple network connections in a single end to end association, the transport layer Stream Control Transmission Protocol (SCTP) can enable seamless and transparent communication sessions over multiple heterogeneous networks. This paper analyzes the performance of multimedia distribution when making use of two multihomingSCTPbasedapproaches: Single Path Transfer and Concurrent Multi-path Transfer, in which a single or all paths within an association are used simultaneously for data transmission. In this investigation various retransmission policies and different parameter sets are used in turn and recommendations are made for achieving best results during video delivery. In order to perform this study a novel realistic evaluation tool-set was proposed and is described, which can simulate video delivery over SCTP. Our simulation results and analysis show how to optimize the transmission of multimedia content over SCTP associations in both single and multipath scenarios. INDEX TERMS-Concurrent multi-path transfer, multi-homing, multimedia distribution, SCTP, single path transfer
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