• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.136-145
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• 2001

As with appearing new applications that requires QoS guarantee such as VoIP, VPN in Internet, problems of IP QoS has been one of most important issues in next-generation Internet. IETF has proposed integrated services model(Int-Serv) and differentiated service(Diff-Serv) to supply IP QoS in Internet. Int-Serv model uses the state information of each IP flow, so satisfies QoS according to traffic characteristics, but increases the amount of flow state information with increasing flow number. Diff-Serv model uses PHP(Per Hop Behavior), and there are well-defined classes to provide differentiated traffics with different services according to delay and loss sensitivity. Diff-Serv model can provide diverse services in Internet because of having no the state and signal information of each flow. As MPLS uses the packet forwarding technique based-on label, it implements the traffic engineering in the networks easily. The MPLS can set up the path with different traffic parameters, and assign each path to particular Class of Services. Therefore it is possible to support the Diff-Serv model with well-defined classes. In this paper we investigate the performance improvement of Diff-Serv function in the MPLS network to guarantee class of services in Internet.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.721-723
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• 2004

오늘날의 인터넷은 QoS를 보장하기 위해 다양한 방법을 사용하고 있는데, 본 논문에서는 Integrated-QoS 개념을 제안하고 이를 기반으로 Admission Control을 실행하는 Enhanced Differentiated Service(DiffServ)를 설계하였다. 본 논문은 IntServ(Integrated Service)와 DiffServ(Differentiated Service)의 장점을 결합하여, EF 클래스에 속하는 다수의 흐름들(flows)에 기존보다 QoS가 더욱 보장된 서비스를 제공할 수 있는 방안을 제시한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.694-698
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• 2002

원격 교육의 서비스질의 문제는 지금까지 원격교육이 원격교육 기술의 확보와 컨텐츠확보 및 다양한 매체 영역확장의 과정이라 볼 수 있다. 인터넷 상에서 단순히 텍스트를 제시하고 이에 적절한 답을 피드백 하는 구조에서 적절한 그래픽 인터페이스구사 동영상 및 효과음 등의 멀티미디어 적 요소로의 진행 과정이 그것이다. 이제 이러한 초기 단계에서 사이버대학, 상업적 원격교육 등이 점차 중요한 현재 교육의 대안으로 되면서 원격교육의 서비스 질이 중요하게 되었다. 본 연구에서는 이러한 원격교육의 서비스 질 확보를 위한 현재 제안되고 구현되고 있는 기술들을 제시하고자 한다. 이로서는 IntServ 모델의 문제점을 극복하기 위해 제안된 DiffServ 모델은 현재 이의 구현을 위한 연구개발이 진행 중에 있다. 제안된 DiffServ 구조 및 지금까지 진행되어온 연구개발 현황 분석 등을 통해 제안된 DiffServ의 문제점과 대안 등을 검토하였다.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.7 no.1
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• pp.33-39
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• 2007

Recently there are increasing needs for Internet and various kinds of contents. These traffics for various contents need more amount of data to provide high-quality information and require various QoS depending on the characteristics of contents. However, current Internet service supports BE (Best Effort) service only, therefore IntServ (Integrated Service) scheme and DiffServ (Differentiated Service) scheme are represented to support QoS in IP layer. This paper describes new scheme that provides QoS taking into account the traffic characteristics over Mobile IPv6 network based on IEEE 802.11e by decreasing signal process time using traffic class of DiffServ and MAC and evaluates the performance through computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.349-354
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• 2006

In 3G networks interworking with external IP-based networks, provision of end-to-end QoS to packet-based services is a critical issue. In this paper, we propose DiffServ-aware Multiple Protocol Label Switching(MPLS) as a new policy enforcement means. With the adoption of the proposed DiffServ-aware MPLS, it is feasible to provide differentiated QoS provision with the help of DiffServ as well as to improve network utilization by using multiple paths based on MPLS. We verify the effectiveness of our proposed policy enforcement means through a simulation in which realtime traffic and non-realtime traffic are served together.

• 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.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.338-341
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• 2005

Recently there are increasing needs for Internet and various kinds of contents. These traffics for various contents need more amount of data to provide high-quality information and require various QoS depending on the characteristics of contents. However, current Internet service supports BE (Best Effort) service only, therefore IntServ (Integrated Service) scheme and DiffSserv (Differentiated Service) scheme are represented to support QoS in IP layer. This paper describes new scheme that provides QoS taking into account the traffic characteristics over Mobile IPv6 network based on IEEE 802.11e by decreasing signal process time using traffic class of DiffServ and evaluates the performance through computer simulation.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.2075-2078
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• 2002

Internet became the most popular network in spite of its weakness in realtime multimedia service. Many experts believe that the Internet has the potential to become the main multimedia distribution network of the near future. Currently, it does not provide any (BoS guarantees and, even when it does, guaranteed quality delivery of video may turn out to be too expensive. Unavoidable packet losses and delay jitter caused by congestion in a best effort delivery environment require use of intelligent transport techniques for effective video delivery. According to market needs of better quality of service (QoS) fur realtime multimedia services over Internet, they have been standardizing RSVP, IntServ, and DiffServ This paper combines the benefits of QoS mechanisms such as RSVP/IntServ with scalable video encoding. We propose that more important bit stream is given more priority such that limited network resources are guaranteed far the stream. Various prioritizing approaches are proposed and compared to normal approach by using Network Simulator. The calculated QoS parameters such as packet loss rate are used to calculate degree of degradation in video quality. In this Paper, proposed methods can be implemented adaptively to Von protocol, such as H.323, SIP.