• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.265-267
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• 2001

본 논문에서는 QoS 멀티캐스트를 지원하기 위한 대역폭 브로커에 대하여 논한다. 현재 인터넷에서 QoS를 확장성있게 지원하기 위한 기술로 DiffServ가 대표적으로 적용되고 있으며, 해당 기술에서 특정 DiffServ 도메인내의 대역폭관리와 DiffServ 도메인간의 동적인 대역폭 관리는 대역폭 브로커라는 모듈에 의해서 수행된다. 본 논문에서는 멀티캐스트 라우터와의 연동기능을 기반으로하여, 다수의 사용자에게 QoS를 만족시킬수 있는 멀티캐스트 트래픽 전송을 지원하는 대역폭 브로커에 대하여 논한다. 해당 대역폭 브로커는 멀티캐스트 그룹내의 사용자의 가입/탈퇴에 따라 효과적으로 대역폭을 관리할 수 있다.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.25-28
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• 2000

As Internet users and network traffics are explosively increased, many researches have been done to provide fast and guaranteed Internet services. The results of these efforts are Multiprotocol Lab el Switching(MPLS) and differentiated service(Diff serv) emerging as a next generation backbone net work. In this paper, we make a research on gearing (or interworking) two technology needed to support end-to-end QoS and explain sequential procedure. And we simulate the L-LSP/E-LSP proposed by Working Group of IETF to be deployed to the DiffServ module which is implemented based on the MPLS network simulator and analyze the performance of the simulation result.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1219-1222
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• 2006

3GPP에서는 단대단 QoS 보장을 위해 정책 기반 망 관리(PBNM:Policy-based Network Management) 방식을 적용할 것을 권고하고 있다. 본 논문에서는 3GPP에서 제시하는 핵심망 구조에 정책 기반 망 관리 기법 중 DiffServ를 적용해서 현재 DSCP(Differentiated Service Code Point)는 8bit 구성되어 있으나 그 중 6bit만 사용되고 있고, 사용하지 않는 이 2bit를 사용하여 DF(Default Forwarding), EF(Expedited Forwarding), AF(Assured Forwarding)의 DSCP에 Service Class Code Point를 부여해서 DiffServ를 서비스하는 망에서 동일한 Diffserv 정책을 설정해서 효율적인 QoS 기법을 제안하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1351-1354
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• 2001

본 논문에서는 Differentiated Services (DiffServ) 망의 edge 라우터에 적용되는 3 단계 트래픽 제어기 (3 phased traffic conditioner : 3PTC)를 제안하였다. 제안된 3PTC 는 TCP 트래픽의 예약된 대역폭 (reserved rate) 의 차이, UDP/TCP의 상호작용, RTT 및 집합된 트래픽을 구성하는 작은 트래픽 수에 의한 영향을 최소화함으로써, DiffServ 망에서 제공하는 Assured Services 사용자들에게 공정한 대역폭을 보장해 줄 수 있다. 3PTC 는 토큰버킷 단계, 확률결정 단계, 그리고 버퍼관리 단계로 이루어져 있다.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.240-243
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• 2003

본 논문에서는 Agere Systems사의 네트워크 프로세서를 사용한 고성능 IP-DiffServ/IP-MPLS 시스템의 구조를 제안하고 성능을 분석한다. 제안한 시스템은 기가비트 이더넷 뿐만 아니라 ATM과 POS 등 다양한 인터페이스를 제공하며 코어 및 에지 라우터로서 MPLS LER 또는 LSR로의 역할을 수행한다. 성능분석은 OPNET을 사용하여 시스템을 모델링한 후 입력 트래픽에 대해서 DiffServ 클래스별 지연시간과 지연의 주된 원인을 분석한다. 그리고 이를 바탕으로 시스템의 성능을 극대화할수 있는 네트워크 프로세서의 최적 파라메터를 도출한다. 성능분석 결과, 시스템이 각 서비스 클래스에 대해서 원활한 서비스를 제공하기 위해서는 프리미엄 서비스에는 최고의 우선순위를 부여하여 큐에 데이터 블럭들이 찰 때 마다. 즉시 서비스해 주어야 한다는 것을 알 수 있었다. 그리고 트래픽이 특정 출구 라인카드로 몰리는 핫스팟이 발생할 경우 트래픽의 지연이 증가하게되는데 이 지연의 주요 원인은 출구 라인카드에서의 큐잉에 의한 것임을 알 수 있었다.

• ETRI Journal
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• v.26 no.1
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• pp.27-37
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• 2004

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.550-564
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• 2012

In this work we propose a new pricing scheme for the wireless Internet services over WiMAX system. First, let us review the characteristics of wireless network which is based on multi-hop relay WiMAX system. Next, we show why usage-based and QoS-aware pricing scheme is needed in the wireless Internet. After that, we propose a theoretical model for the price of multimedia services called a DAP (DiffServ-aware pricing) scheme for the WiMAX multimedia network which takes into account the consumed radio resource of WiMAX system as well as the supported QoS in the IP backbone network. Finally, we present explicit formulae for the packet price, price of consumed radio resource, and price of consumed bytes.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.131-140
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• 2004

With a rapid development of DWDM and photonic switching, $MP{\lambda}S$ network can realize DiffServ like QOS services using optical wavelength mapping to the traffic flows. In this study, we describe the service connection architecture for providing QOS service between $MP{\lambda}S$ network and network users. We also describe a methodology, which is similar to DiffServ mechanism, to build traffic conditioning blocks that can be used to provide the negotiated QOS services using traffic control components defined by IETF

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.735-742
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• 2007

We propose an effective packet marking algorithm for video streaming in DiffServ network. Because legacy packet markers such as srTCM(single rate three color marker) cannot distinguish the importance of packet, these markers can cause quality degradation of streaming during the network congestion period. Recently proposed TMS (Two Marker System) [4] shows effectiveness in such scenario that video streaming service is struggling with other types of service traffic. However, if many video streaming services co-exist in DiffServ network and result in competition among themselves, then both legacy packet markers and even TMS cannot prevent drastic streaming quality degradation. To cope with this, we suggest A-TCPM (Adaptive time sliding window Three Color Marker) algorithm. In this algorithm, an A-TCPM module decides the color of a racket based upon the probability which is lead by current channel status and frame importance ratio. Simulation results show that proposed A-TCPM algorithm can enhance streaming service quality especially when overbooked video streaming sessions struggle with themselves.

• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.58-68
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• 2006

There are two traditional scheduling methods known as PQ and WRR in the DiffServ network, however, these two scheduling methods have some drawbacks. In this paper, we propose an algorithm that can be adopted in WRR scheduler with making up for weak points of PQ and WRR. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assign the weight of WRR scheduler with checking the Queue status of each class. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. From simulation results, the proposed algorithm improves the packet loss rate of the EF class traffic to 6.5% by comparison with WRR scheduling method and that of the AF4 class traffic to 45% by comparison with PQ scheduling method.