• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.319-321
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• 2000

현재 인터넷이 제공하는 최선의 서비스(best-effort)를 개선하기 위해서 IETF(Internet Engineering Task Force)의 DiffServ(Differentiated Service)WG에서는 현재의 인터넷 서비스를 보다 차별화된 QoS를 제공할 수 있도록 하는 방안으로서 Differentiated Service를 제안하였다. 본 논문에서는 이러한 Differentiated Service의 개념과 구조를 살펴보고 Differentiated Service에서 트래픽 포워딩을 효율적으로 제공하기 위한 하나의 방법으로서 CBQ를 이용한 패킷 전송 기법을 제안한다. 본 논문에서 제안하고 있는 이러한 방법을 통해 서비스 측면에서 어느 정도까지의 QoS를 보장할 수 있는지를 실험적으로 보이고자 한다.

• 전자공학회논문지 IE
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• v.48 no.3
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• pp.16-19
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• 2011

Differentiated Service is an IP QoS ensuring method based on packet marking that allows packets to be prioritized according to user requirements. During the time of congestion, more low priority packets are dropped than high priority packets. Different policy models are used to determine how to mark the packet. This paper investigated the performance of Differentiated Service using time sliding window with 3 color marking (TSW3CM). Simulation results using NS-2 showed that Differentiated Service can provide the quality of service requirements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.282-287
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• 1998

최근 인터넷에서는 Mbone, 인터넷 폰과 같이 End-to-End QoS (Quality of Service) 보장을 요구하는 많은 실시간 멀티미디어 응용들이 출현하고 있다[1]. 인터넷 표준 기구인 IETF (Internet Engineering Task Force)에서는 과거 수년간, 이러한 실시간 멀티미디어 응용들을 지원하기 위한 Integrated Service 구조를 개발하고 자원 예약 프로토콜로서 RSVP (Resource Reservation Protocol)를 개발하였다. 하지만, flow를 기본 단위로 하여 자원을 예약하고 패킷을 처리하는 Integrated Service 모델은 인터넷에 광역적으로 구축되기에는 너무 복잡한 것으로 드러났다. 이에 따라, 큰 규모의 인터넷 전달망에 적용할 경우 scalability 문제를 안고 있는 Integrated Service 모델의 대안 또는 보완책으로, Differentiated Service 구조가 작년부터 IETF에서 활발히 논의되어 왔다. [2,3,4]. 본 논문에서는 Differentiated Service의 구조 및 구성요소의 개념을 살펴보고, RSVP/Integrated Service 구조와 어떻게 공존하여 광역 인터넷에서 End-to-End QoS를 제공할 수 있을지를 고찰한 다음, 향후 기술 발전을 전망한다.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.228-239
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• 2013

Peer-to-peer (P2P) systems have proved the most effective and popular file sharing applications in recent years. Previous studies mainly focused on equal service and differentiated service strategies when peers have no initial data before their downloads. For an upload-constrained P2P file sharing system, we model both the equal service process and the differentiated service process when the initial data distribution of peers satisfies some special conditions. Moreover, we show how to minimize the time required to distribute the file to any number of peers. The proposed fluid-based models can reveal the intrinsic relations among the initial data amount, the peer set size, and the minimum last finish time. The closed-form expressions derived from the extended models can closely approximate chunk-based models and systems, especially for relatively large files. As an application of the extended models, we show how to provide differentiated service efficiently to multiple peer sets. Since no limits are imposed on the upload bandwidth of peers or the size of each peer set, we believe that our analytic process and the results achieved can provide not only fundamental insights into bandwidth allocation and data scheduling but also a helpful reference for both improving system performance and building an effective incentive mechanism for P2P file sharing systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7B
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• pp.697-710
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• 2004

Differentiated services (DiffServ) model has been prevailed as a scalable approach to provide quality of service in the Internet. However, there are difficulties in providing the guaranteed service in terms of end-to-end systems since differentiated services network considers quality of service of aggregated traffic due to the scalability and many researches have been mainly focused on per hop behavior or a single domain behavior. Furthermore quality of service may be time varying according to the network conditions. In this paper, we study dynamic class mapping mechanism to guarantee the end-to-end quality of service for multimedia traffics with the minimum network cost over differentiated services network. The proposed algorithm consists of an effective implementation of relative differentiated service model, quality of service advertising mechanism and dynamic class mapping mechanism. Finally, the experimental results are provided to show the performance of the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1191-1199
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• 2009

As the Internet service evolves from the best effort data service to a multimedia service such as a mix of voice, data and video, a need for the guarantee of the quality of service to network services became one of the hot issues for the network operators. On the other hand, the introduction of the multimedia services over the IP network requires a managed differentiated service that adopts a prioritized treatment of packets. This incurs a need for a differentiated pricing scheme for the packets that receive different level of quality of service. This work proposes an analytic framework about packet pricing scheme for these services, and investigate the effect of service differentiation to the packet price for each class. Via numerical experiment, we validate our argument and illustrate the implication of the work.

• IE interfaces
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• v.23 no.2
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• pp.193-202
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• 2010

The quality of service(QoS) model should be presented with the optimal network design to effectively provide the multimedia data services between users and converged services with mobile or TV in the next-generation Internet. In specific, the method to provide differentiated services for each user is needed in the given Internet node to offer the previously negotiated QoS with the user. In this paper, the performance of the QoS enabling technologies in the differentiated services(DiffServ) network domain is analyzed. The QoS offering model and QoS metrics are presented to analyze the performance of the major scheduling algorithms. Under the real network topology and virtual service scenarios in the university, the NS-2 network simulation based on the discrete-event is performed. The results show that the ratio-based scheduling method is more effective rather than the bandwidth-assignment method.

• Journal of Industrial Technology
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• v.20 no.B
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• pp.139-146
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• 2000

To support Quality of Service (QoS) in the existing Internet, Differentiated Service (Diff-Serv) has been proposed. But, the unfairness between TCP connections remains as a serious problem not only in the conventional best-effort service Internet but also in new Diff-Serv network. In this paper, we propose the Balancing Marker Algorithm (BMA) improving the fairness between individual connections of aggregated sources in a Diff-Serv network. This algorithm is based on the 3-level priority marking method. We compared the 2-level packet priority marker with the Balancing Marker proposed in this paper. And we showed that the BMA improved the fairness and the throughputs between the individual connections with different delays in an aggregated source.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.9-12
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• 2000

Today, QoS is one of the most critical issues in the network research area and Differentiated Services (DiffServ) is considered as the most prominent solution to provide some kinds of service differentiation without introducing any scalability problem. Among DiffServ's approaches, Assured Service (AS) provides some minimal level of QoS guarantee by treating more preferably than traditional Best Effort (BE) traffic and by using different level of drop probabilities within the same AS classes. In this paper, we investigate the ECN's capability of improving overall goodput of the flows and the possibility of resolving the fairness problem among the flows belonging to same class in Differentiated Services architecture.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.124-126
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• 2002

Voice over Internet Protocol(VoIP) is expected to be a major application on the Internet in the future This paper propose an approach to VoIP that uses Differentiated Service and Multi-protocol Label Switching(MPLS) to provide quantitative QoS guarantees over an IP network. An algorithm that determines QoS-constrained routes is proposed and a framework that uses such an algorithm for traffic engineering is outlined. the key component of this framework is a Centralize Resource Manager(CRM) responsible for monitoring and managing resources within the network and making all decisions to route／reroute traffic according to QoS requirement