• Journal of the Korea Society of Computer and Information
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• v.9 no.2
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• pp.139-147
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• 2004

To provide Internet QoS, the IETF Proposed two models of Integrated Services (IntServ) and Differentiated Services (DiffServ) Unlike IntServ where resource reservation and admission control is Per-flow based using RSVP. DiffServ supports aggregated traffic classes to provide various QoS to different classes of traffics. However a dynamic QoS management system is required to dynamically provide differentiated QoS for customers who require dynamic QoS change. This paper designed and implemented therefore a policy-based QoS management system to manage effectively and configure dynamically QoS of DiffServ networks. The validity of the system has been verified by the experimentation on the Linux-based DiffServ network.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.613-620
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• 2006

From both techlical and economic viewpoints, DiffServ IP QoS architecture is accepted as a more practical solution because of the complexity Problem of the other IntServ architecture. In this paper, we propose several models to support DiffServ QoS in DSL broadband access networks and discuss about migration path from current best-effort DSL networks to DiffServ-enabled ones. Since DSL networks are recently and widely deployed in the world amount ot new investment, compatibility with existing QoS-unaware DSL systems, and compatibility with existing charging systems as well as effective support of various QoS services must be carefully considered when we design DiffServ QoS support models in DSL networks. The DiffServ models proposed in this paper are divided into static DiffServ models and dynamic DiffServ models which are near-term solutions and long-term solutions repecitively. The static DiffServ models include Flat DiffServ which suworts per-subscriber DiffServ QoS and Structured DiffServ which supports per-subscriber and per-service DiffServ QoS. And the dynamic DiffServ models include Direct DiffServ for P2P(Peer to Peer) applications and Indirect DiffServ for ASP(Application Service Provider) applications.

• Journal of KIISE:Information Networking
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• v.34 no.1
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• pp.73-80
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• 2007

This paper presents an approach to support dynamic QoS(Quality of Service) requirements of largely emerging SIP(Session Initiation Protocol) multimedia applications in broadband access networks. The topology of QoS-enabled broadband access networks and its operational model to support SIP QoS are firstly suggested. And then the procedures to bind QoS-enabled SIP signaling into an IP QoS mechanism are presented. In this paper, DiffServ-based IP QoS architecture is deployed due to the complexity problem of the other IntServ architecture, and COPS(Common Open Policy Service) and COPS-PR protocol based signaling mechanisms are used to support dynamic DiffServ QoS, correspondent with dynamic SIP QoS. The broadband access network is assumed to support rapidly expanding Metro Ethernet 802.1 D/Q QoS, and how to translate SIP QoS parameters into IP DiffServ classes and DiffServ classes into 802.1 D/Q QoS parameters is also presented in this paper.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.45-54
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• 2002

MPLS(Multiprotocol Label Switching) is regarded as a core technology for migrating to the next generation Internet. In this paper, we propose an dynamic flow admission control supporting DiffServ(Differentiated Services) to provide QoS in MPLS networks. Our proposed model dynamically adjusts the amount of admissible traffic based on transmittable capacity over one outgoing port. It then transmits the Packets while avoiding congested area resulting traffic loss. Ingress LSRs find out the congested area by collecting network state information at QoS state update for QoS routing table. Our Proposed model manages the resource efficiently by protecting the waste of resources that is a critical Problem of DiffServ and makes much more flows enter the network to be served.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1613-1616
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• 2000

DiffServ 네트웍 모델은 기존의 Best Effort 서비스를 지원하는 IP 네트웍에 차별화된 서비스를 지원 할 수 있는 IP QoS를 무리없이 도입하기 위하여 제안되었다. DiffServ 네트웍은 IntServ에서와 같은 Scalability 문제를 해소할 수 있도록 Edge-to-Edge QoS를 지원하기 용이한 단순화된 구조를 가지고 있다. 이러한 단순화시킨 네트웍 구조에서 여러 가지 QoS 요구 특성을 가지는 트래픽에게 서비스를 제공하고, 네트웍 자원의 이용 효율을 극대화 하고자 하는 사업자의 요구에 따라 효율적인 자원 할당 방안이 필요하게 된다. 자원 활용의 효율을 제고하기 위해서는 정밀하고 동적인 자원할당 방식을 이용하는 것이 필요하며, 이를 실현하기 위하여 Intra-domain의 Edge-to-Edge Path 상에 있는 노드에서의 트래픽 부하 측정을 바탕으로, DSCP 제어 코드를 사용한 탐색 패킷을 통하여 Intra-domain의 부하 및 자원 할당 수준을 탐색하고, 이를 기반으로 Admission Control을 중심으로 한 Resource Provisioning을 동적으로 수행할 수 있는 메커니즘을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.325-338
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• 2004

As the recent rapid development of internet technology and the wide spread of multimedia communication, massive increase of network traffic causes some problems such as the lack of network paths and the bad quality of service. To resolve these problems, this paper presents a traffic control agent that can perform the dynamic resource allocation by controlling traffic flows on a DiffServ network. In addition, this paper presents a router that can support DiffServ on Linux to support selective QoS in IP network environment. To implement a method for selective traffic transmission based on priority on a DiffServ router, this paper changes the queuing discipline in Linux, and presents the traffic control agent so that it can efficiently control routers, efficiently allocates network resources according to service requests, and relocate resources in response to state changes of the network. Particularly for the efficient processing of Assured Forwarding(AF) Per Hop Behavior(PHB), this paper proposes an ACWF$^2$Q$^{+}$ packet scheduler on a DiffServ router to enhance the throughput of packet transmission and the fairness of traffic services.s.

• 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.

• 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.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.3 s.345
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• pp.135-143
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• 2006

PQ(Priority Queue) and WRR(Weighted Round Robin) are the most famous schedulers, however, these schedulers have both points of advantages and disadvantages. In this paper, we propose an algorithm that can be adopted in my kind of scheduling type with making up for weak points of PQ and WRR. The proposed algorithm includes a fuzzy theory in the scheduler to assign priorities dynamically in the DiffServ network. This algorithm produces the control discipline by the fuzzy theory to assign priorities of the Queue effectively with checking the Queue status of each class dynamically under the discipline.

• Journal of Korea Multimedia Society
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• v.7 no.5
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• pp.698-712
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• 2004

DiffServ network architecture does not define a call admission control procedure explicitly. In this paper, a new DiffServ QoS control mechanism is suggested which, after the call admission control, can execute packet process according to the class while, at the same time, executing on the flow based call admission control in the DiffServ network. Routers on the path from the source to the destination estimate the aggregated class traffic of the existing flows and the new incoming flow and then, perform a call admission control in accordance with the type of classes efficiently based on the required bandwidth per each class that can meet the user's QoS requirements. In order to facilitate the packet process according to the class after the flow based call admission control, a mechanism is suggested that can adjust the network resources to classes dynamically. The performance analysis on this mechanism is carried out through a simulation.