• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2015년도 제52차 하계학술대회논문집 23권2호
• /
• pp.275-276
• /
• 2015

네트워크 가상화를 위한 대표적인 개방적 아키텍처로 OpenFow를 들 수 있다. OpenfFow는 가상 네트워크(Software Defined Network) 개념을 실현하기 위한 랜 스위치 제어 프로토콜의 집합체로서 데이터 센터 등 주로 유선랜 환경을 목표로 설계되어 활용되고 있다. 이 논문에서는 OpenFlow를 무선랜의 AP(Access Point)에 적용하여 WiFi 디바이스들로 구성된 가상 무선 네트워크 관리 프레임을 구현한다. 구현된 관리 프레임은 WiFi 디바이스들의 토폴로지와 트래픽 상황을 중앙 관제 센터에서 모니터링할 수 있고, 플로우 경로를 설정함으로써 라우터를 경유하지 않고 AP 수준에서 스위칭(라우팅)이 가능하여 전체적인 트래픽 혼잡을 크게 줄일 수 있다.

• Journal of Information Processing Systems
• /
• 제16권4호
• /
• pp.896-914
• /
• 2020

With the rapid growth of network traffic, a large number of connected devices, and higher application services, the traditional network is facing several challenges. In addition to improving the current network architecture and hardware specifications, effective resource management means the development trend of 5G. Although many existing potential technologies have been proposed to solve the some of 5G challenges, such as multiple-input multiple-output (MIMO), software-defined networking (SDN), network functions virtualization (NFV), edge computing, millimeter-wave, etc., research studies in 5G continue to enrich its function and move toward B5G mobile networks. In this paper, focusing on the resource allocation issues of 5G core networks and radio access networks, we address the latest technological developments and discuss the current challenges for resource management in 5G.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제16권7호
• /
• pp.2257-2285
• /
• 2022

Cyber-physical systems (CPS) have been growing exponentially due to improved cloud-datacenter infrastructure-as-a-service (CDIaaS). Incremental expandability (scalability), Quality of Service (QoS) performance, and reliability are currently the automation focus on healthy Tier 4 CDIaaS. However, stable QoS is yet to be fully addressed in Cyber-physical data centers (CP-DCS). Also, balanced agility and flexibility for the application workloads need urgent attention. There is a need for a resilient and fault-tolerance scheme in terms of CPS routing service including Pod cluster reliability analytics that meets QoS requirements. Motivated by these concerns, our contributions are fourfold. First, a Distributed Non-Recursive Cloud Model (DNRCM) is proposed to support cyber-physical workloads for remote lab activities. Second, an efficient QoS stability model with Routh-Hurwitz criteria is established. Third, an evaluation of the CDIaaS DCN topology is validated for handling large-scale, traffic workloads. Network Function Virtualization (NFV) with Floodlight SDN controllers was adopted for the implementation of DNRCM with embedded rule-base in Open vSwitch engines. Fourth, QoS evaluation is carried out experimentally. Considering the non-recursive queuing delays with SDN isolation (logical), a lower queuing delay (19.65%) is observed. Without logical isolation, the average queuing delay is 80.34%. Without logical resource isolation, the fault tolerance yields 33.55%, while with logical isolation, it yields 66.44%. In terms of throughput, DNRCM, recursive BCube, and DCell offered 38.30%, 36.37%, and 25.53% respectively. Similarly, the DNRCM had an improved incremental scalability profile of 40.00%, while BCube and Recursive DCell had 33.33%, and 26.67% respectively. In terms of service availability, the DNRCM offered 52.10% compared with recursive BCube and DCell which yielded 34.72% and 13.18% respectively. The average delays obtained for DNRCM, recursive BCube, and DCell are 32.81%, 33.44%, and 33.75% respectively. Finally, workload utilization for DNRCM, recursive BCube, and DCell yielded 50.28%, 27.93%, and 21.79% respectively.

• KNOM Review
• /
• 제22권1호
• /
• pp.1-10
• /
• 2019

필요한 자원 수를 결정하는 과정은 여러 가지 요인에 따라 달라진다. 자동스케일링은 광범위한 요인에 기초하여 결정하는 메커니즘 중 하나이며 NFV에서 중요한 과정이다. SDN의 출현 이후 네트워크가 클라우드로 전환되고 있기 때문에, 앞으로 더 나은 자원 관리 필요하다. 이 문제를 해결하기 위해; 네트워크 기능의, 하이퍼스레딩 오버헤드, 요청 수, 실행 시간 등의 요인에 따라 VNFM이 가상 시스템 리소스를 자동 스케일링할 수 있는 솔루션을 제안한다. 하이퍼스레드 가상 코어가 물리적 코어처럼 완전히 작동하지 않는다는 것은 알려진 사실이다. 또한, 다양한 코어의 유형이 다르기 때문에 코어 수를 계산하는 프로세스는 정확하고 정밀하게 측정할 필요가 있다. 플랫폼 독립성은 API를 통해 모니터링 마이크로서비스 솔루션을 제안함으로써 달성된다. 따라서 본 논문에서는 오토스케일링 애플리케이션과 모니터링 마이크로 서비스를 사용하여 네트워크의 기준을 충족하기 위해 리소스 프로비저닝 프로세스를 강화하는 메커니즘을 제안한다.

• 한국통신학회논문지
• /
• 제41권12호
• /
• pp.1914-1924
• /
• 2016

본 논문은 5G 모바일 네트워크에서 가상화 기반의 이동통신 코어망인 Virtualized Evolved Packet Core(vEPC) 환경을 고려하여, 가입자의 종류 및 트래픽 식별에 따라 동적으로 End-to-end 서비스를 제공하기 위한 기술인 Service Function Chaining(SFC)을 적용하기 위한 구조 및 메시지 절차를 제안한다. SFC 기술은 네트워크 기능들을 물리적인 연결에 상관없이 선택적으로 제공하기 위한 기술로써, 가상화 기반 네트워크 기술인 Network Function Virtualization(NFV)기반의 네트워크 환경에서 서비스 제공을 위한 주요 기술로 예상된다. 특히, 5G 모바일 코어 네트워크는 분산 코어 형태로 구축될 것으로 예상되기 때문에 본 논문에서는 이를 고려하여 계층적 SFC(hSFC: Hierarchical SFC) 구조를 적용하였다. 본 논문에서는 제안하는 구조 및 구조 내에서의 SFC를 이용한 경로 설정 메시지 절차를 정의하고 오픈소스 기반의 테스트베드 설계를 통해 이를 구현하고자 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권2호
• /
• pp.514-535
• /
• 2019

Information-centric networks operate under the assumption that all network components have built-in caching capabilities. Integrating the caching strategies of information centric networking (ICN) with wireless virtualization improves the gain of virtual infrastructure content caching. In this paper, we propose a framework for software-defined information centric virtualized wireless device-to-device (D2D) networks. Enabling D2D communications in virtualized ICN increases the spectral efficiency due to reuse and proximity gains while the software-defined network (SDN) as a platform also simplifies the computational overhead. In this framework, we propose a joint virtual resource and cache allocation solution for latency-sensitive applications in the next-generation cellular networks. As the formulated problem is NP-hard, we design low-complexity heuristic algorithms which are intuitive and efficient. In our proposed framework, different services can share a pool of infrastructure items. We evaluate our proposed framework and algorithm through extensive simulations. The results demonstrate significant improvements in terms of visiting latency, end user QoE, InP resource utilization and MVNO utility gain.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권12호
• /
• pp.4364-4384
• /
• 2021

The dynamic network state and the mobility of the terminals make the service function chain (SFC) orchestration mechanisms based on static and deterministic assumptions hard to be applied in SDN/NFV mobile edge computing networks. Designing dynamic and online SFC orchestration mechanism can greatly improve the execution efficiency of compute-intensive and resource-hungry applications in mobile edge computing networks. In order to increase the overall profit of service provider and reduce the resource cost, the system running time is divided into a sequence of time slots and a dynamic orchestration scheme based on an improved column generation algorithm is proposed in each slot. Firstly, the SFC dynamic orchestration problem is formulated as an integer linear programming (ILP) model based on layered graph. Then, in order to reduce the computation costs, a column generation model is used to simplify the ILP model. Finally, a two-stage heuristic algorithm based on greedy strategy is proposed. Four metrics are defined and the performance of the proposed algorithm is evaluated based on simulation. The results show that our proposal significantly provides more than 30% reduction of run time and about 12% improvement in service deployment success ratio compared to the Viterbi algorithm based mechanism.