Fairness-oriented overlay VPN topology construction

An important issue in dynamically constructed Virtual Private Networks (VPN) is how the overlay topology is created and maintained. Classical VPN topologies, such as hub-and-spoke or full-mesh, fail to remain convenient and viable when the number of nodes grows to as little as a few tens. Convenient topology formation mechanisms should be distributed, should permit incremental and dynamic operations, and should limit the number of nodes a new entry connects with. In this work, we show that approaches devised to create “short” networks, while yielding a significant total network throughput, may be severely affected by unfairness issues, i.e., different pair of nodes may experience a widely different throughput performance. Hence, we introduce a fairness-oriented topology formation algorithm for VPN. The proposed algorithm is incremental, meaning that the addition of a new node to the overlay topology does not imply rewiring of already established overlay links. Simulation results show that our proposed approach achieves high fairness levels, as quantified in terms of well known Jain's fairness index, meanwhile retaining satisfactory throughput performance

Enabling large scale cloud services by software defined wide area network

Interconnecting data centers (DCs) efficiently and using the fully available capacity of existing resources in Wide Area Network (WAN) seems to be one of the most challenging issues for service providers (SPs). In this master memory, we investigate a new approach to optimize traffic engineering in WAN which interconnects DCs (Inter-DC WAN) using Software Defined Networking (SDN). We propose a model to optimize bandwidth allocation to flows belonging at different Classes of Services (CoS) according to their priority and the current network state. The proposed model aims to maximize the throughput in the network and to minimize the overall energy consumption. The proposed model takes into account inter-domain communication and respects underlying technology specifications such as Multi-Protocol Label Switching (MPLS). To build our model, we consider four mathematical expressions for energy consumption of the topology nodes and links namely: the idle, the fully proportional, the agnostic and the step increasing models, and we adopt the MPLS model for Inter-DC WAN. We propose a deterministic algorithm to solve the optimization problem using Linear Programming (LP) solvers and we compare its performances with two existing models: Microsoft solutions’ SWAN which focuses on throughput maximization, and a base line model which aims to minimize energy consumption while allocating bandwidth to different flows. Experiments in the simulation environment show that the proposed solution can optimally exploit available physical capacity in the network to afford users demand in terms of bandwidth and uses the minimum energy to carry traffic. The proposed optimization model is NP-hard, so we propose a greedy heuristic to improve the runtime of the proposed solution

Virtual Cluster Management for Analysis of Geographically Distributed and Immovable Data

Thesis (Ph.D.) - Indiana University, Informatics and Computing, 2015Scenarios exist in the era of Big Data where computational analysis needs to utilize widely distributed and remote compute clusters, especially when the data sources are sensitive or extremely large, and thus unable to move. A large dataset in Malaysia could be ecologically sensitive, for instance, and unable to be moved outside the country boundaries. Controlling an analysis experiment in this virtual cluster setting can be difficult on multiple levels: with setup and control, with managing behavior of the virtual cluster, and with interoperability issues across the compute clusters. Further, datasets can be distributed among clusters, or even across data centers, so that it becomes critical to utilize data locality information to optimize the performance of data-intensive jobs. Finally, datasets are increasingly sensitive and tied to certain administrative boundaries, though once the data has been processed, the aggregated or statistical result can be shared across the boundaries. This dissertation addresses management and control of a widely distributed virtual cluster having sensitive or otherwise immovable data sets through a controller. The Virtual Cluster Controller (VCC) gives control back to the researcher. It creates virtual clusters across multiple cloud platforms. In recognition of sensitive data, it can establish a single network overlay over widely distributed clusters. We define a novel class of data, notably immovable data that we call "pinned data", where the data is treated as a first-class citizen instead of being moved to where needed. We draw from our earlier work with a hierarchical data processing model, Hierarchical MapReduce (HMR), to process geographically distributed data, some of which are pinned data. The applications implemented in HMR use extended MapReduce model where computations are expressed as three functions: Map, Reduce, and GlobalReduce. Further, by facilitating information sharing among resources, applications, and data, the overall performance is improved. Experimental results show that the overhead of VCC is minimum. The HMR outperforms traditional MapReduce model while processing a particular class of applications. The evaluations also show that information sharing between resources and application through the VCC shortens the hierarchical data processing time, as well satisfying the constraints on the pinned data

Service-Driven Networking

This thesis presents our research on service-driven networking, which is a general design framework for service quality assurance and integrated network and service management in large scale multi-domain networks. The philosophy is to facilitate bi-party open participation among the users and the providers of network services in order to bring about better service customization and quality assurance, without sacrificing the autonomy and objectives of the individual entities. Three primary research topics are documented: service composition and adaptation, self-stabilization in uncoordinated environment, and service quality modeling. The work involves theoretical analysis, algorithm design, and simulations as evaluation methodology

Virtualization to build large scale networks

Abstract. There is not much research concerning network virtualization, even though virtualization has been a hot topic for some time and networks keep growing. Physical routers can be expensive and laborious to setup and manage, not to mention immobile. Network virtualization can be utilized in many ways, such as reducing costs, increasing agility and increasing deployment speed. Virtual routers are easy to create, copy and move. This study will research into the subjects of networks, virtualization solutions and network virtualization. Furthermore, it will show how to build a virtual network consisting of hundreds of nodes, all performing network routing. In addition, the virtual network can be connected to physical routers in the real world to provide benefits, such as performance testing or large-scale deployment. All this will be achieved using only commodity hardware

Mobile Network Virtualization: A study of the techno-economic aspects

Οι τηλεπικοινωνιακοί πάροχοι σήμερα, έρχονται αντιμέτωποι με την συνεχώς αυξανόμενη ζήτηση δεδομένων ενώ καλούνται να βρίσκουν οικονομικά συμφέρουσες λύσεις για να καλύψουν αυτήν την ανάγκη. Ενώ γίνονται προσπάθειες να αυξηθεί ο ρυθμός που μεταδίδονται τα δεδομένα και να αυξηθεί η απόδοση στο φυσικό επίπεδο, κυρίως με την εισαγωγή της τεχνολογίας LTE, η ζήτηση για χρήση των πόρων είναι πολύ μεγαλύτερη από αυτά που μπορούν να προσφέρουν οι πάροχοι. Για τον λόγο αυτό κρίνεται αναγκαία η καλύτερη αξιοποίηση των δικτυακών πόρων. Το μοντέλο που επικρατούσε μέχρι σήμερα του διαμοιρασμού συγκεκριμένων πόρων δεν θεωρείται εποικοδομητικό. Επομένως κρίνεται απαραίτητη η αξιοποίηση της τηλεπικοινωνιακής υποδομής με νέες μεθόδους αυξάνοντας τα έσοδα ανά χρήστη και μειώνοντας τα έξοδα. Για τον λόγος αυτό γίνεται πλέον λόγος για τον όρο Network Virtualization. Πρόκειται για μία μέθοδο που έχει εφαρμοστεί επιτυχώς στα ενσύρματα δίκτυα και συμβάλλει στην απλοποίηση των δικτύων καθώς και στον καλύτερο διαμοιρασμό των πόρων. Οι όροι Software Defined Networks και Network Function Virtualization έχουν επίσης την ίδια βάση και αποσκοπούν στην καλύτερη αντιμετώπιση της μεγάλης ζήτησης με τον καλύτερο δυνατό τρόπο. Στην παρούσα διπλωματική θα εξετάσουμε τον τρόπο που εφαρμόζονται οι παραπάνω έννοιες στα κινητά δίκτυα και θα γίνει μία προσπάθεια παρουσίασης των τεχνο-οικονομικών μεταβλητών σχετικών με κόστη κεφαλαίου και λειτουργικά κόστη.One of the most indubitable challenges faced by the mobile network operators is to provide cost effective solutions to meet the growing demand of the mobile traffic. Whilst every effort has been made to increase the data rates and improve the physical layer performance especially with the introduction of Long Term Evolution-Advanced (LTE/LTE-A) systems, it is not sufficient to meet the exponential increase in traffic demand that is expected to become one order of magnitude larger than the bandwidth that the operators will be able to provide. As a consequence, operators need to achieve a better utilization of the scarce mobile network resources. However, the conventional business model followed by the network operators, based on a dedicated network infrastructure paradigm where each operator have access to a fixed set of network resources is no more considered a valuable approach for efficient radio resource management and utilization. Consequently, the mobile network operators are investigating new and innovative technologies to be able to effectively and efficiently utilize their network infrastructure while increasing the ARPU (Average Revenue Per User) and decrease the capital expenditure (CAPEX) and (OPEX) operational expenditures. To this end, aiming to avoid the underutilization of the physical resources, recently there has been a surge of interest for leveraging the benefits of Network Virtualization in mobile cellular networks. Network Virtualization (NV) has been successfully applied in wired networks as a means to provide abstraction of the network equipment and dramatically simplify the network configuration and resource management. The most prominent NV instances, such as Software Defined Networking (SDN) and Network Function Virtualization (NFV), are also envisioned by the mobile network operators as a way to address the explosive capacity demand of mobile traffic and reduce the costs burden faced to handle the increasing traffic demand. Accordingly, in this dissertation, we will discuss the ways to apply NV in telecoms and especially in mobile networks. This is supported by a techno-economic analysis so as to consider its effect on CAPEX and OPEX expenditures

Grid'5000: a large scale and highly reconfigurable grid experimental testbed

Large scale distributed systems such as Grids are difficult to study from theoretical models and simulators only. Most Grids deployed at large scale are production plat-forms that are inappropriate research tools because of their limited reconfiguration, control and monitoring capa-bilities. In this paper, we present Grid’5000, a 5000 CPU nation-wide infrastructure for research in Grid computing. Grid’5000 is designed to provide a scientific tool for com-puter scientists similar to the large-scale instruments used by physicists, astronomers, and biologists. We describe the motivations, design considerations, architec-ture, control, and monitoring infrastructure of this experi-mental platform. We present configuration examples and performance results for the reconfiguration subsystem

Traffic engineering in dynamic optical networks

Traffic Engineering (TE) refers to all the techniques a Service Provider employs to improve the efficiency and reliability of network operations. In IP over Optical (IPO) networks, traffic coming from upper layers is carried over the logical topology defined by the set of established lightpaths. Within this framework then, TE techniques allow to optimize the configuration of optical resources with respect to an highly dynamic traffic demand. TE can be performed with two main methods: if the demand is known only in terms of an aggregated traffic matrix, the problem of automatically updating the configuration of an optical network to accommodate traffic changes is called Virtual Topology Reconfiguration (VTR). If instead the traffic demand is known in terms of data-level connection requests with sub-wavelength granularity, arriving dynamically from some source node to any destination node, the problem is called Dynamic Traffic Grooming (DTG). In this dissertation new VTR algorithms for load balancing in optical networks based on Local Search (LS) techniques are presented. The main advantage of using LS is the minimization of network disruption, since the reconfiguration involves only a small part of the network. A comparison between the proposed schemes and the optimal solutions found via an ILP solver shows calculation time savings for comparable results of network congestion. A similar load balancing technique has been applied to alleviate congestion in an MPLS network, based on the efficient rerouting of Label-Switched Paths (LSP) from the most congested links to allow a better usage of network resources. Many algorithms have been developed to deal with DTG in IPO networks, where most of the attention is focused on optimizing the physical resources utilization by considering specific constraints on the optical node architecture, while very few attention has been put so far on the Quality of Service (QoS) guarantees for the carried traffic. In this thesis a novel Traffic Engineering scheme is proposed to guarantee QoS from both the viewpoint of service differentiation and transmission quality. Another contribution in this thesis is a formal framework for the definition of dynamic grooming policies in IPO networks. The framework is then specialized for an overlay architecture, where the control plane of the IP and optical level are separated, and no information is shared between the two. A family of grooming policies based on constraints on the number of hops and on the bandwidth sharing degree at the IP level is defined, and its performance analyzed in both regular and irregular topologies. While most of the literature on DTG problem implicitly considers the grooming of low-speed connections onto optical channels using a TDM approach, the proposed grooming policies are evaluated here by considering a realistic traffic model which consider a Dynamic Statistical Multiplexing (DSM) approach, i.e. a single wavelength channel is shared between multiple IP elastic traffic flows

Reducing Internet Latency : A Survey of Techniques and their Merit

Bob Briscoe, Anna Brunstrom, Andreas Petlund, David Hayes, David Ros, Ing-Jyh Tsang, Stein Gjessing, Gorry Fairhurst, Carsten Griwodz, Michael WelzlPeer reviewedPreprin