Yazar "Guler, Evrim" seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    Evaluating Path Selection Strategies with Blockchain-based Routing in Multi-Domain SDNs
    (Institute of Electrical and Electronics Engineers Inc., 2022) Guler, Evrim; Karakus, Murat; Uludag, Suleyman
    Software-Defined Networking (SDN) has emerged as one of the most prolific inventions in the general area of computer communications over the past decade. Among many of the touted benefits, SDN architecture facilitated by OpenFlow has the potential to help network administrators to provide End-to-End (E2E) Quality of Service (QoS)-guaranteed paths for flows among networks while providing finer-granular flow management along with global network view. In our previous work, we have introduced QoSChain to amalgamate the advantages of blockchain and SDN for inter-network QoS provisioning to orchestrate an agile and software-driven traffic management framework in order to facilitate cross-network policy automation, assurance, E2E visibility, control and validation. In this study, we focus on the impact of the path selection strategies on the performance of the overall QoSChain performance. Specifically, we exploit three simple but effective path selection strategies, First Feasible Path Selection (FFPS), Random Feasible Path Selection (RFPS), and Minimum Hop Path Selection (MHPS), to evaluate their performance, impact, and overhead in terms of the flow setup time, message overhead, and network resource consumption metrics. Our preliminary simulations results show that the path selection plays an important role in the overall performance with hop count minimization delivering a superior performance offset by an initial higher setup times. © 2022 IEEE.
  • Küçük Resim Yok
    Öğe
    Genetic algorithm enabled virtual multicast tree embedding in Software-Defined Networks
    (Academic Press Ltd- Elsevier Science Ltd, 2023) Guler, Evrim; Karakus, Murat; Ayaz, Furkan
    The recent network virtualization technology enables the multi-tenancy, where various virtual network requests can share the same physical network by decoupling network services from the underlying hardware architecture. The process of virtual node and link mapping onto a shared Substrate Network (SN) by satisfying the requested network resources (i.e., bandwidth, computing capacity, etc.) is referred to as Virtual Network Embedding (VNE), which is known as an NP-Hard problem. The problem of VNE aims to exhibit one-to-one (unicast) communication. However, the motivation of this research is to explore how to efficiently map virtual networks with one-to-many (multicast) communications, which are in the form of Virtual Multicast Trees (VMTs), onto an SN. This problem differs from the traditional VNE problem and has not been well-studied by the research community. To this end, we propose a novel algorithm, Modified Genetic Algorithm for Virtual Multicast Tree Embedding (MGA-VMTE), to embed VMTs onto a shared SN in this research. The proposed MGA-VMTE algorithm focuses on minimizing the network resource consumption (i.e., bandwidth) under end-to-end delay constraint in the SN while satisfying the computing request of virtual nodes. Our extensive simulations demonstrate that the MGA-VMTE algorithm outperforms the dynamic impact factor and traditional greedy-based virtual multicast tree embedding approaches regarding bandwidth consumption, acceptance ratio, and resource depletion ratio metrics on NSFNET, USNET, Random-60 node, and Random-120 node network topologies.
  • Küçük Resim Yok
    Öğe
    QoSChain: Provisioning Inter-AS QoS in Software-Defined Networks With Blockchain
    (IEEE-Inst Electrical Electronics Engineers Inc, 2021) Karakus, Murat; Guler, Evrim; Uludag, Suleyman
    Data flows of various applications, such as video conferencing, telesurgery, online-gaming, etc., require particular treatment regarding Quality of Service (QoS) because of their sensitivity to such parameters as high bandwidth, low delay, and so on. However, provisioning of QoS-based routing services across Autonomous Systems (ASes) poses gruelling challenges due to the distributed nature and business confidentially hesitations. This study presents a novel blockchain-aided QoS-enabled inter-AS routing framework, QoSChain (QC), by blending merits of Software-Defined Networking (SDN) and Blockchain technologies. QC framework introduces a coordination framework with mutually distrusting participants that eliminates centralized mediators in provisioning QoS among SDN-enabled ASes. Also, QC reduces the time to set up an end-to-end (E2E) path and the number of messages exchanged and processed by SDN controllers for a QoS flow. Furthermore, it alleviates the concerns of network operators regarding potentially sensitive information disclosure resulting from the required information sharing for QoS-based cross-AS paths by masking details of any confidential information. Experimental results verify the feasibility of the proposed framework on E2E QoS-based routing among SDN networks. This work aims at being a useful primer for researchers in providing insights on how blockchain can be deployed in QoS-enabled routing.
  • Küçük Resim Yok
    Öğe
    RoutingChain: A Proof-of-Concept Model for a Blockchain-Enabled QoS-Based Inter-AS Routing in SDN
    (IEEE, 2020) Karakus, Murat; Guler, Evrim
    A Software-Defined Networking (SDN) architecture and OpenFlow can help network administrators to provide end-to-end (E2E) Quality of Service (QoS)-guaranteed paths for flows among networks while providing finer-granular flow management along with global network view. In this context, we introduce a proof-of-concept for a blockchain-enabled QoS-based inter-Autonomous System (AS) routing framework, RoutingChain, that blends a QoS-concerned routing model and blockchain technology. This study's contributions can mainly be stated in five-fold: (i) Competitors-tailored routing coordination framework, (ii) eliminating centralized mediators while coordinating QoS-based inter-AS routing, (iii) an emerging use-case for blockchain technology in networking, (iv) reducing the number of QoS signaling-based message overhead, and (v) mitigating privacy/security concerns in inter-AS routing. Experimental results indicate that the blockchain technology can be applied on E2E QoS-based routing among networks. To the best of our knowledge, this is the first study exploiting the merits of blockchain technology to establish a novel coordination framework for QoS-enabled inter-AS routing in SDN.
  • Küçük Resim Yok
    Öğe
    SpectrumChain: An Efficient Spectrum Management Framework in Blockchain-Enabled Flexible SDONs
    (IEEE, 2022) Guler, Evrim; Karakus, Murat; Uludag, Suleyman
    Huge potentials of optical networks provide an excellent choice in meeting the exponential growth in bandwidth demand. In particular, Elastic Optical Networks (EONs), with its promising potentials in increased availability, failure resilience, load -balancing, new use cases for on -demand opportunities, and efficient resource allocations, are good candidates for the future high-speed networks. When EONs are augmented with the emerging Software Defined Networking (SDN), that decouples the data and control planes, an agile and synergistic combination emerges under a general term of SDN-based optical networking (SDON), albeit with operational challenges. In this paper, we introduce a blockchain-enabled QoS-based inter-Internet Service Provider (ISP) routing coordination framework for SDONs, SpectrumChain (SC), to eliminate centralized mediators and reduce QoS signaling overhead. Experimental results show that the SC framework can effectively handle the QoS-enabled inter-ISP routing in SDON architecture in terms of flow setup time, message overhead, and requests serviced as compared to the traditional approaches.