Isolation Schemes of Virtual Network Platform for Cloud Computing

( Sungwon Ahn ),( Shinhyoung Lee ),( Seehwan Yoo ),( Daeyoung Park ),( Dojung Kim ),( Chuck Yoo ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.11

Network virtualization supports future Internet environments and cloud computing. Virtualization can mitigate many hardware restrictions and provide variable network topologies to support variable cloud services. Owing to several advantages such as low cost, high flexibility, and better manageability, virtualization has been widely adopted for use in network virtualization platforms. Among the many issues related to cloud computing, to achieve a suitable cloud service quality we specifically focus on network and performance isolation schemes, which ensure the integrity and QoS of each virtual cloud network. In this study, we suggest a virtual network platform that uses Xen-based virtualization, and implement multiple virtualized networks to provide variable cloud services on a physical network. In addition, we describe the isolation of virtual networks by assigning a different virtualized network ID (VLAN ID) to each network to ensure the integrity of the service contents. We also provide a method for efficiently isolating the performance of each virtual network in terms of network bandwidth. Our performance isolation method supports multiple virtual networks with different levels of service quality.

Design of an Efficient Method for Identifying Virtual Machines Compatible with Service Chain in a Virtual Network Environment

Hyeonseok Oh,Daeun Yu,Yoon-Ho Choi,Namgi Kim 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.11

With advancements in network technologies, network virtualization has been proposed to efficiently provide a large number of services and flexible management by utilizing limited resources over existing networks as much as possible. Network virtualization has been proposed as a new paradigm for networks, as it simplifies complicated network configurations for convenient maintenance through the maximum utilization of limited network resources. However, problems have arisen due to network virtualization, such as how to assign real network components that are compatible with virtual network components over a large number of virtual machines existing in a network. In particular, the service-chaining concept—where a network flow only passes through needed services—has been newly introduced by combining the recently highlighted Software-Defined Network with a virtualization concept called Network Function Virtualization. As a result, studies on which virtual machines are selected and how to connect them have increased ever more. Accordingly, this paper aims to identify virtual machines that are compatible with service chaining in a virtual network environment where virtual machines are dispersed, and it proposes a method of how to create a path by connecting virtual machines.

라우터 가상화 환경에서의 10G 이더넷 카드를 위한 네트워크 성능 분석

이치영(Chiyoung Lee),김도중(Dojung Kim),이종원(Jong-Won Lee),유혁(Hyuck Yoo) 한국정보과학회 2011 정보과학회논문지 : 정보통신 Vol.38 No.6

가상 네트워크는 논리적인 네트워크로, 다수의 가상 네트워크가 하나의 물리적 자원을 공유하여 동작한다. 따라서 가상 네트워크는 물리적인 네트워크의 구축에 비해 적은 비용으로 네트워크를 구축할 수 있다. 이러한 가상 네트워크를 구축하기 위해 요구되는 요소 중의 하나가 가상 라우터이다. 최근에는 고성능 PC 기반 플랫폼 상에서 가상 라우터를 구현하려는 연구도 진행되고 있다. 가상 라우터에서는, 한 가상 라우터의 동작 상태에 의해, 자원을 공유하고 있는 다른 가상 라우터가 영향을 받지 않아야 한다. 이러한 고립을 제공하기 위해 시스템 가상화 기술을 사용한다. 하지만 가상화 기술은 가상화에 따른 I/O 성능 열화의 문제가 있다. 특히, 라우터에서는 패킷의 송수신에 따른 I/O 작업이 많기 때문에, 이 I/O 성능 문제를 반드시 해결해야 한다. 본 논문에서는 가상 라우터 간의 고립을 보장하면서 가상화에 따른 I/O 오버헤드를 극복하기 위하여, Xen 기반 SR-IOV 기술을 적용한다. 그리고 실험을 통하여 SR-IOV 기술이 가상 라우터의 성능 향상에 효과가 있음을 보인다. 또한, 구축한 가상 라우터 상에서의 네트워크 성능을 측정하고 이를 분석한다. 이를 통해, 가상화 오버헤드 외에, 라우팅 과정과 멀티 코어 환경의 동기화 작업이 가상 라우터 성능 저하의 주요 원인임을 보인다. A virtual network is a kind of a logical network, and several virtual networks shares common physical resources. Therefore, compared to implement a physical network, a virtual network has a merit to be efficiently implemented in cost. A virtual router is a key component to implement virtual networks. Recently, researches of virtual routers on high performance commodity HW have been conducted. To support stable virtual networks, each virtual router does not affected by other virtual routers on the same physical platform. Generally, server virtualization techniques can be used to support isolation among virtual routers. However, the virtualization technique shows low I/O performance due to virtualization overhead. Because routers have executed many I/O operations to receive and transmit packets, the I/O overhead in virtualization should be avoided to implement high performance virtual routers This paper implements the Xen-based virtual router for isolation among routers, and reduces the virtualization overheads using SR-IOV to improve the I/O performance. And we show the performance effects by SR-IOV through an experiment. Also, we measure and analyze the performance of our virtual router. In here, We certificate a fact that the routing process and multi-core environment are reasons of the low network performance in the virtual router. This fact will be a foundation to develop some methods for network performance improvement in the virtual router.

Virtual Network Mapping Algorithm Based on Load Balancing

Ming Jiang,Xijie Tang,Min Zhang,Ziyang Li 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.9

Recent studies for network virtualization have shown a promising way to overcome the Internet ossification. The one of the key issues in network virtualization is a virtual network mapping problem, i.e., mapping a virtual network to the physical network. The situations of dynamic arrivals of virtual network request and the limited life cycle of the virtual networks pose significant challenges to the virtual network mapping problem. A balance between the resource allocation of the physical network and the number of mapped virtual networks. In this paper, we have considered the time characteristics that virtual network requests when mapping algorithms so as to achieve the objective that the node load and link load can simultaneously reach a balance. Giving full consideration to mutual restraints of time and resources, we propose a two-dimensional discrete weighted model based on time and resources, and establish a mathematical programming model of minimizing the degree of two-dimensional load balancing. Moreover, we devise a VN embedding algorithms LB-VNE. Simulation experiments show that the proposed algorithms can increase the acceptance ratio and the revenue by the substrate network in the long term.

Survey on Network Virtualization Using OpenFlow: Taxonomy, Opportunities, and Open Issues

( Ahmed Abdelaziz ),( Tan Fong Ang ),( Mehdi Sookhak ),( Suleman Khan ),( Athanasios Vasilakos ),( Chee Sun Liew ),( Adnan Akhunzada ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.10

The popularity of network virtualization has recently regained considerable momentum because of the emergence of OpenFlow technology. It is essentially decouples a data plane from a control plane and promotes hardware programmability. Subsequently, OpenFlow facilitates the implementation of network virtualization. This study aims to provide an overview of different approaches to create a virtual network using OpenFlow technology. The paper also presents the OpenFlow components to compare conventional network architecture with OpenFlow network architecture, particularly in terms of the virtualization. A thematic OpenFlow network virtualization taxonomy is devised to categorize network virtualization approaches. Several testbeds that support OpenFlow network virtualization are discussed with case studies to show the capabilities of OpenFlow virtualization. Moreover, the advantages of popular OpenFlow controllers that are designed to enhance network virtualization is compared and analyzed. Finally, we present key research challenges that mainly focus on security, scalability, reliability, isolation, and monitoring in the OpenFlow virtual environment. Numerous potential directions to tackle the problems related to OpenFlow network virtualization are likewise discussed

가상팀의 지식네트워크, IT 활용, 성과 간의 관계에 관한 연구

신경식(Kyung Shik Shin),서아영(A Young Suh) 한국경영학회 2009 經營學硏究 Vol.38 No.1

A virtual team is defined as a group of people that works across space, time, and organizational boundaries with links strengthened by the diverse computer-mediated communication media. By forming virtual teams, people can easily collaborate with other people and acquire information and knowledge from anywhere and at anytime. However, managing virtual teams is far more challenging than managing traditional teams because ad hoc virtual teams may engage in a lower level of social interacts and supports than their counterparts in face-to-face environments. The problem of how to manage social relationships among virtual team members to increase their performance is considered to be very pivotal and still remains unsolved. Through the lens of social networks, this study examines the following specific questions: (1) to what extent should ad hoc virtual teams maintain internal cohesion; (2) whether do virtual team members’ external bridging ties guarantee the higher level of team performance; and (3) how does IT play the role in balancing and harmonizing internal cohesion and external bridging ties for increasing the performance of a virtual team. We investigate these questions with the specific type of social networks; the knowledge networks which contain knowledge or task-related intelligence in the networks. These knowledge networks contain the collective competencies that enable organizational members to produce products and services. By examining the influence of knowledge networks of virtual teams on their performance, this study aims to reveal how to manage knowledge network among members to maximize the performance of a virtual team. The contributions of this study are three-fold. First, we conceptually clarify the properties of knowledge networks that individuals maintain within and outside their work groups: network density and group-level structural holes. Next, by integrating social network theory and CMC related theories, we develop a theoretical framework linking knowledge networks, IT use, and team performance. Third, we examine the interplay among the research constructs and elucidate a complex phenomenon in relations to the forming and managing knowledge networks of a virtual team, which is in short supply in the current literature. The proposed model was tested with 172 consultants and 42 virtual teams in 5 global consulting companies in Korea. The study found that increasing network intra-group network density was crucial for better team performance. On the contrary, increasing extra-group structural holes decreased the team performance, contradicting the prevailing wisdom. The most important standpoint is that the effect of knowledge network of virtual teams varied along the level of IT use that is related to communal CMC such as group ware or group decision support systems (GDSS). This study is meaningful in that it examined how to manage knowledge network by integrating social network theory and computer-mediation communication theory, and by analyzing the moderating effect between knowledge network and IT use in the context of virtual teams. Based on these findings, the study suggests that optimal knowledge network configurations to maximize the performance of a virtual team should be considered along with the IT use.

Providing survivability for virtual networks against substrate network failure

( Ying Wang ),( Qingyun Chen ),( Wenjing Li ),( Xuesong Qiu ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.9

Network virtualization has been regarded as a core attribute of the Future Internet. In a network virtualization environment (NVE), multiple heterogeneous virtual networks can coexist on a shared substrate network. Thus, a substrate network failure may affect multiple virtual networks. In this case, it is increasingly critical to provide survivability for the virtual networks against the substrate network failures. Previous research focused on mechanisms that ensure the resilience of the virtual network. However, the resource efficiency is still important to make the mapping scheme practical. In this paper, we study the survivable virtual network embedding mechanisms against substrate link and node failure from the perspective of improving the resource efficiency. For substrate link survivability, we propose a load-balancing and re-configuration strategy to improve the acceptance ratio and bandwidth utilization ratio. For substrate node survivability, we develop a minimum cost heuristic based on a divided network model and a backup resource cost model, which can both satisfy the location constraints of virtual node and increase the sharing degree of the backup resources. Simulations are conducted to evaluate the performance of the solutions. The proposed load balancing and re-configuration strategy for substrate link survivability outperforms other approaches in terms of acceptance ratio and bandwidth utilization ratio. And the proposed minimum cost heuristic for substrate node survivability gets a good performance in term of acceptance ratio.

가상화 시스템에서 Virtio와 SR-IOV 적용에 대한단일 및 다중 네트워크 성능 평가 및 분석

이재학,임종범,유헌창 한국정보처리학회 2024 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.13 No.2

As functions that support virtualization on their own in hardware are developed, user applications having various workloads areoperating efficiently in the virtualization system. SR-IOV is a virtualization support function that takes direct access to PCI devices, thusgiving a high I/O performance by minimizing the need for hypervisor or operating system interventions. With SR-IOV, network I/Oacceleration can be realized in virtualization systems that have relatively long I/O paths compared to bare-metal systems and frequentcontext switches between the user area and kernel area. To take performance advantages of SR-IOV, network resource management policiesthat can derive optimal network performance when SR-IOV is applied to an instance such as a virtual machine(VM) or container arebeing actively studied.This paper evaluates and analyzes the network performance of SR-IOV implementing I/O acceleration is comparedwith Virtio in terms of 1) network delay, 2) network throughput, 3) network fairness, 4) performance interference, and 5) multi-network. The contributions of this paper are as follows. First, the network I/O process of Virtio and SR-IOV was clearly explained in the virtualizationsystem, and second, the evaluation results of the network performance of Virtio and SR-IOV were analyzed based on various performancemetrics. Third, the system overhead and the possibility of optimization for the SR-IOV network in a virtualization system with high VMdensity were experimentally confirmed. The experimental results and analysis of the paper are expected to be referenced in the networkresource management policy for virtualization systems that operate network-intensive services such as smart factories, connected cars,deep learning inference models, and crowdsourcing. 하드웨어 자체적으로 가상화를 지원하는 기능들이 추가됨에 따라 다양한 작업 유형을 가진 사용자 어플리케이션들이 가상화 시스템에서 효율적으로 운용되고 있다. 가상화 지원 기능 중 SR-IOV는 PCI 장치에 대한 직접 접근을 통해 하이퍼바이저 또는 운영체제 개입을 최소화하여 시스템성능을 높이는 기술로 베어-메탈 시스템 대비 비교적 긴 I/O 경로 및 사용자 영역과 커널 영역에 대한 빈번한 컨텍스트 스위칭 등 가상화 계층의추가로 낮은 네트워크 성능을 가진 가상화 시스템에서 네트워크 I/O 가속화를 실현하게 해준다. 이러한 성능적 이점을 이용하기 위해 가상머신또는 컨테이너와 같은 인스턴스에 SR-IOV를 접목할 시 최적의 네트워크 I/O 성능을 도출할 수 있는 네트워크 자원 관리 정책이 활발히 연구되고있다. 본 논문은 I/O 가속화를 실현하는 SR-IOV의 네트워크 성능을 1) 네트워크 지연 시간, 2) 네트워크 처리량, 3) 네트워크 공정성, 4) 성능간섭,5) 다중 네트워크와 같은 측면으로 세밀한 성능 평가 및 분석을 Virtio와 비교하여 진행한다. 본 논문의 기여점은 다음과 같다. 첫째, 가상화 시스템에서 Virtio와 SR-IOV의 네트워크 I/O 과정을 명확히 설명했으며, 둘째, Virtio와 SR-IOV의 네트워크 성능을 다양한 성능 메트릭을 기반으로 분석하였다. 셋째, 가상머신 밀집도가 높은 환경에서 SR-IOV 네트워크에 대한 시스템 오버헤드 및 이에 대한 최적화 가능성을 실험으로 확인하였다. 본논문의 실험 결과 및 분석들은 스마트 팩토리, 커넥티드-카, 딥러닝 추론 모델, 크라우드 소싱과 같은 네트워크 집약적인 서비스들을 운용하는가상화 시스템에 대한 네트워크 자원 관리 정책에 활용될 것으로 기대된다

Optimized Provisioning of SDN-enabled Virtual Networks in Geo-distributed Cloud Computing Datacenters

Khaled Alhazmi,Abdallah Shami,Ahmed Refaey Hussein 한국통신학회 2017 Journal of communications and networks Vol.19 No.4

Cloud computing provides on-demand IT services vialarge distributed datacenters over high-speed networks. Virtualization,a key cloud computing technology, allows service providersto offer computing services in cloud environments without platformcompatibility discrepancies. The recent proliferation of cloudcomputing has rekindled interest in network virtualization. Thus,network virtualization is emerging as a polymorphic approachfor the future Internet that will facilitate the use of shared resources. Virtual network provisioning is considered to be a mainresource allocation challenge in any virtualized network environment. Software-defined networking (SDN) imparts flexibility toa network by removing the control layer from the data transferlayer of the network and moving it to the control plane. Networkvirtualization is further employed to share physical infrastructureto enable multiple service providers to access the network. Flexibleaccess requires efficient management of network resources; theSDN control plane can be used for efficient management of virtualnetworks. In this study, we formulate virtual network provisioningin SDN-enabled, geographically distributed cloud computing datacentersas a mixed integer linear programming (MILP) problem. The formulation of the proposed optimized virtual network provisioning(OVNP) model is studied by means of simulations. The performanceof the proposed approach is measured against enhancednetwork cloud provisioning (ENCP), our previous research, andother recognized research focused on the ratio of successfully provisionedrequests and the efficiency of resource utilization. The resultsverify the effectiveness of the proposed approach.

네트워크 기반 제어를 위한 LonWorks/IP 라우터의 설계 및 구현

현진욱(Jin Wook Hyun),최기상(Gi Sang Choi),최기홍(Gi Heung Choi) 대한전기학회 2007 대한전기학회 학술대회 논문집 Vol.2007 No.4

Demand for the technology for access to device control network in industry and for access to building automation system via internet is on the increase. In such technology integration of a device control network with a data network such as internet and organizing wide-ranging DCS(distributed control system) is needed, and it can be realized in the framework of VDN(virtual device network). Specifications for device control network and data network are quite different because of the differences in application. So a router that translates the communication protocol between device control network and data network, and efficiently transmits information to destination is needed for implementation of the VDN(virtual device network), This paper proposes the concept of NCS(networked control system) based on VDN(virtual device network) and suggests the routing algorithm that uses embedded system.