• International Journal of Computer Science & Network Security
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• 제24권2호
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• pp.67-78
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• 2024

Software-Defined Networking (SDN) is a new emerging networking paradigm that has adopted a logically centralized architecture to increase overall network performance agility and programmability. Combining network virtualization with SDN will guarantees for combined advantages of improved flexibility and network performance. Combining SDN with hypervisors divides the network physical resources into several logical transparent and isolated virtual SDN network (vSDN), where each has its virtual controller. However, SDN hypervisors bring several advantages as well as several challenges to its network operators as for the virtual appliances, their efficient placement, assurance of network performance is mandatory, and their dynamic instantiation with their migration. In this article, we provide a brief and concise review of network virtualization along with its implementation in the SDN network. SDN hypervisors types are discussed, and taxonomy is provided to demonstrate the importance of hypervisors in SDN. A comparison of SDN hypervisors is performed to elaborate on the vital hypervisor software along with their features, and different challenges are discussed faced by the SDN network. A framework is proposed to add combined functionalities of hypervisors to create a more effective and efficient virtual system. The purpose of the framework is to increase network performance through proper configuration of resources, software, control plane isolation functions with defined rules and policies.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2007년도 춘계학술대회
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• pp.181-188
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• 2007

In this paper, the management thoughts of The network-manufacture based on virtual-agile organization is Brief summarized, then an explanation had been made about the virtual circulation economy patterns paradigm, which is integrated the virtual-agile manufacture and circulation economy theory, the critical content of this paradigm, at last we recognized the virtual-agile organization pattern circulation economy is one important trend of the network-manufacture development in the future.

• ETRI Journal
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• 제43권5호
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• pp.932-940
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• 2021

Currently, research on network functions virtualization focuses on using microservices in cloud environments. Previous studies primarily focused on communication between nodes in physical infrastructure. Until now, there is no sufficient research on group key management in virtual environments. The service is composed of microservices that change dynamically according to the virtual service. There are dependencies for microservices on changing the group membership of the service. There is also a high possibility that various security threats, such as data leakage, communication surveillance, and privacy exposure, may occur in interactive communication with microservices. In this study, we propose an ID-based group key exchange (idGKE) mechanism between microservices as one group. idGKE defines the microservices' schemes: group key gen, join group, leave group, and multiple group join. We experiment in a real environment to evaluate the performance of the proposed mechanism. The proposed mechanism ensures an essential requirement for group key management such as secrecy, sustainability, and performance, improving virtual environment security.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.265-268
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• 1998

This paper evaluates the VSN(Virtual switch Network) characteristics in the internal call processing of IMT-2000 switching system, which is composed of VSN instead of ATM switch network. In results, internal call establishment delay is increased approximately 5.4msec than the conventional ATM switching system. The evaluated condition is the load 0.8, and the 100km distance between VSNs. It is confirmed that the VSN has the potentiality in the practical implementation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2783-2804
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• 2021

In the network function virtualization environment, dynamic changes in network traffic will lead to the dynamic changes of service function chain resource demand, which entails timely dynamic adjustment of service function chain resource configuration. At present, most researches solve this problem through virtual network function migration and link rerouting, and there exist some problems such as long service interruption time, excessive network operation cost and high penalty. This paper proposes a dynamic adjustment method of service function chain resource configuration for the dynamic changes of network traffic. First, a dynamic adjustment request of service function chain is generated according to the prediction of network traffic. Second, a dynamic adjustment strategy of service function chain resource configuration is determined according to substrate network resources. Finally, the resource configuration of a service function chain is pre-adjusted according to the dynamic adjustment strategy. Virtual network functions combination and virtual machine reusing are fully considered in this process. The experimental results show that this method can reduce the influence of service function chain resource configuration dynamic adjustment on quality of service, reduce network operation cost and improve the revenue of service providers.

• 정보과학회 논문지
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• 제43권11호
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• pp.1223-1232
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• 2016

가상 네트워크 기술은 다양한 서비스의 요구조건을 반영한 네트워크를 제공할 수 있다. 다양한 서비스의 요구조건을 반영하기 위해 효율적인 리소스 분배 기술이 필요하다. 기존의 트래픽 대역폭 분배 기법들은 다운링크 트래픽만 제어하거나 네트워크의 트래픽 상황을 고려하지 않는다. 무선 네트워크에서 다운링크와 업링크는 같은 자원을 공유한다. 또한, 기존의 트래픽 대역폭 분배 기법들은 모든 스테이션이 포화된 트래픽을 발생시킨다고 가정한다. 그래서 기존의 트래픽 대역폭 분배 기법들은 가상 무선 네트워크에서 트래픽 제어를 할 수 없다. 본 논문에서는 이러한 문제들을 해결하기 위해 트래픽 기반 대역폭 제어 기법을 제안한다. 가상 네트워크에 SDN을 적용하고 각 스테이션의 트래픽을 모니터링하고 비포화 트래픽을 발생시키는 스테이션을 탐색한다. 또한, 모니터링 정보를 기반으로 업링크와 다운링크 트래픽을 동적으로 제어한다. 실제 테스트베드 구성 후, 기존의 기법과 비교 결과, 트래픽 대역폭 분배 성능이 최대 14% 개선되었다.

• International Journal of Computer Science & Network Security
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• 제22권9호
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• pp.137-142
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• 2022

This paper argues for modern technologies in the educational process. It specifically outlines issues germane to virtual and augmented reality. It begins with an account on virtual reality and augmented reality, and touches on their characteristics, the advantages, obstacles and applications. It also discusses some relevant studies that emphasized the role of virtual and augmented reality in education, the difference between two terms. The paper ends with a note of vision on how to activate them in educational institutions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.819-837
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• 2014

Data centers, which implement cloud service, have been faced up with quick growth of energy consumption and low efficiency of energy. 60GHz wireless communication technology, as a new option to data centers, can provide feasible approach to alleviate the problems. Aiming at energy optimization in 60GHz wireless data centers (WDCs), we investigate virtualization technology to assign virtual resources to minimum number of servers, and turn off other servers or adjust them to the state of low power. By comprehensive analysis of wireless data centers, we model virtual network and physical network in WDCs firstly, and propose Virtual Resource Mapping Packing Algorithm (VRMPA) to solve energy management problems. According to VRMPA, we adopt packing algorithm and sort physical resource only once, which improves efficiency of virtual resource allocation. Simulation results show that, under the condition of guaranteeing network load, VPMPA algorithm can achieve better virtual request acceptance rate and higher utilization rate of energy consumption.

• ETRI Journal
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• 제25권6호
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• pp.475-488
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• 2003

In this paper, we propose an efficient and simple fair queuing algorithm, called new starting potential fair queuing (NSPFQ), which has O(1) complexity for virtual time computation and also has good delay and fairness properties. NSPFQ introduces a simpler virtual time recalibration method as it follows a rate-proportional property. The NSPFQ algorithm recalibrates the system virtual time to the minimum virtual start time among all possible virtual start times for head-of-line packets in backlogged sessions. Through analysis and simulation, we show that the proposed algorithm has good delay and fairness properties. We also propose a hardware implementation framework for the scheduling algorithm.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (3)
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• pp.604-606
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• 2002

Virtual LAN 은 기존의 LAN에 비해 물리적인 네트워크에 대해 브로드캐스트 도메인을 위한 사용자 그룹을 독립적으로 가진다. 그러나 Virtual LAN에서 DHCP를 통한 자동 주소 할당을 하는 경우 브로드캐스트 도메인으로 인한 DHCP 의 오동작을 일으켜 주소할당을 할 수 없게 된다. 본 논문에서는 이와 같은 DHCP 의 오동작인 NAK Loop 문제를 알아보고 이를 보완하기 위한 유효 주소 인지 알고리즘을 제시한다. 그리고 그 결과는 실제실험실 환경에서의 프로토콜 분석기를 이용한 패킷 캡쳐를 통해 보여준다.