• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.367-370
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• 2011

Tactical communication environment evolving for the purpose of providing services such as voice, video and text based on ALL-IP. Therefore, To be able to guarantee QoS level which meets the required level of subscriber for these services in the constrained tactical communication infrastructure, it is required to take the characteristics such as wireless transmission link, mobility of troops or personal into service quality scheme. In this paper, to support differentiated QoS for each individual or mission in the tactical communication environment, we presents a technique that can provide same QoS level which was served originally regardless of the situation to user's move through dynamically determining the QoS level to be provided at the time of the service request on VoIP-Switch.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.2
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• pp.31-40
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• 2004

Diff-Serv(DS) is a mechanism by which network service providers can offer differing levels of network service to different traffic, in so providing quality of service(QoS) to their customers. Because this mechanism has been deployed just for fixed hosts with the Token Bucket mechanism according to AggF(Aggregate Flow) instead of each flow, DS can not suggest effective usability of traffic resources. In this paper, we use WFQ mechanism for traffic conditioner and scheduling method monitoring the AggF and the results will be used to control the next flows coming in TC. So it will control traffic rate dynamically and suggest efficient usability of bandwidth.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2B
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• pp.144-156
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• 2003

Internet/Intranet has been continuously enhanced by new emerging IP technologies such as differentiate service(DiffServ), IPSec(IP Security) and MPLS(Multi-protocol Label Switching) traffic engineering. According to the increased demands of various real-time multimedia services, ISP(Internet Service Provider) should provide enhanced end-to-end QoS(quality of service) and security features. Therefore, Internet and Intranet need the management functionality of sophisticated traffic engineering functions. In this paper, we design and implement the performance management functionality for the guaranteed end-to-end QoS provisioning on MPLS-based VPLS(Virtual Private LAN Service). We propose VPLS OAM(Operation, Administration and Maintenance) for efficient performance management. We focus on a scheme of QoS management and measurement of QoS parameters(such as delay, jitter, loss, etc.) using VPLS OAM functions. The proposed performance management system also supports performance tuning to enhance the provided QoS by re-adjusting the bandwidth of LSPs for VPLS. We present the experimental results of performance monitoring and analysis using a network simulator.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3320-3331
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• 1999

In this paper, we explore two ways to improve the bandwidth assurance performance of Assured Service(AS). It is well known that AS fails to meet the bandwidth assurance target for large-profile TCP flows competing with many small-profile flows. This flows after the back-offs induced by packet drops. Thus currently proposed solution to this problem naturally focus on modifying TCP's behavior to counter the unfairness in the TCP dynamics. Unfortunately, these proposals lack practicability in terms of the required changes in the incumbent Internet infrastructure. Admitting this difficulty, we instead look to not yet deployed Diff-Serv mechanisms for practical solutions. In particular, we investigate the role of RIO, RED with IN(in-profile) and OUT(out-profile), queue management scheme in the assurance failure for As. Specifically, we identify the inadequacy of RIO that aggravates the bandwidth assurance failure. Then we alleviates the bandwidth assurance failure problem by separately controlling the out-of-profile packet queue length. Through extensive simulations we demonstrate that RI+O extends the regime where AS consistently provides the bandwidth assurance.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.547-549
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• 2004

본 논문에서는 IP/MPLS 망에서 QoS 보장형 차별화 서비스 제공을 위한 Virtual Networking 구조를 제안한다. 제안한 구조에서는 멀티미디어 단말장치와 PE(Provider Edge) 사이에서 RSVP-TE를 이용한 signalling을 통해 연결설정을 요청하고 PE에서 CAC(Call Admission Control)가 이루어질 수 있도록 한다. 또한 provider network에서 일반 가입자에게 QoS 보장형 차별화 서비스를 제공해줄 수 있도록 Multiple Virtual Network을 구성하며, class-type별로 차별화된 virtual network을 구성하기 위해서 L-LSP를 PE간에 full-mesh 형태로 설정한다 본 논문에서 제안한 Virtual Networking을 통하며 망 사업자는 보다 효율적으로 망을 관리하며, 통신망 자원의 이용율을 극대화시키고 사용자들에게 QoS 보장형 차별화 서비스를 제공해주는 것이 가능하다.

• 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.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.227-233
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• 2003

In paper, we present design and implementation of MPLS based VPN with QoS capabilities. We propose a design architecture of an edge router for MPLS based VPN with QoS capabilities in backbone network. We design functional blocks, interface specifications, detail routing and forwarding information based structure, and packet forwarding engine for the purpose of implementation of an edge router, We extend bgp-4 software for implementation differentiated service packet forwarding schemes in MPLS based VPN.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.310-312
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• 2000

명시적인 자원 할당과 스케줄링에 의해 QoS를 제공 할 수 있는 방안으로 RSVP가 제안되었으나 내부 구조 변경이나 확장성의 문제를 내포하고 있다. 그래서 IETF에서는 차등 서비스(Differentiated Service)를 이용하여 서비스 영역을 확장하려는 연구가 활발히 진행중이다. DiffServ는 확장성을 고려하여 RSVP와 같은 개별 flow에 대한 QoS 제공이 아닌 flow들의 집합(aggregated)으로 차등적인 서비스를 제공하는 방법이다. 본 논문에서는 aggregated flow로 서비스를 제공할 때 불특정 flow에 대한 QoS 손실을 막기 위해 Token Bucket Meter 처리 전에 사전 모니터링에 의해 자원공유의 공정성과 처리 속도를 향상시킬 수 있는 TC(Traffic Conditioner)를 설계, 구현하여 다수 subnetwork에서의 flow가 자원을 공정하게 공유함을 결과로 보였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.421-423
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• 2001

본 논문은 IETF에서 제안한 차등화서비스모델(Differentiated Service Model)을 지원하는 라우터를 리눅스상에 구현하였다. 구현한 라우터는 기존의 리눅스에서 지원하는 에지 라우터의 단점을 개선하기 위하여 구현한 ingress marker를 사용하였다. 구현된 ingress marker는 AF 클래스의 트래픽을 미터링하고 마킹하기 위해 사용되는 trTCM을 포함하고 있으며, 이 ingress marker를 사용한 에지 라우터는 병목이 발생한 경우에도 각 클래스간 독립적으로 서비스를 보장해 줄 수 있다. 각 클래스간 성능보장은 AF PHB를 통해 기존 라우터와 비교 실험하여 검증하였다.