• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.257-260
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• 2001

As today's network infrastructure continues to grow and DiffServ IP networks ate now available to provide various levels of flexible QoS services. DiffServ guarantees good scalability but shows dynamic QoS dependent on network traffic loads. Therefore, in this paper, we investigate the dynamics of DiffSev QoS and present analytical model to estimate the allowable traffic load under the given network conditions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.127-133
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• 2011

This study proposed the PHB mapping model for combining services with DiffServ in the MPLS network capable of high-speed switching, and the effective differential bandwidth service model in the MPLS network on the basis of the proposed mapping model. The result of simulation on the service model using PRI showed that the transmission rate was achieved as much as the assigned bandwidth regardless of the increase of traffic as far as the EF PHB did not exceed the assigned bandwidth at the peak rate when the overall traffic increased.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.128-131
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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 assigns 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. In result, the proposed algorithm enhances the packet discard rate at the EF class than WRR scheduling method and the AF4 class than PQ scheduling method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.947-956
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• 2003

The current IP Routing Protocolspacket networks also need to provide the network QoS based of DiffServ, RSVP, MPLStraffic model which is standardized as IETF reference model for NGN. The first topic of this paper is to propose Traffic-Balanced Routing Protocol(TBRP) to process existing best effort traffic. TBRP will process low priority interactive data and background data which is not sensitive to dealy. Secondly Hierarchical Traffic-Traffic-Scheduling Routing Protocol(HTSRP) is also proposed. HTSRP is the hierarchical routing algorithm for backbone and access networkin case of fixed-wireless convergence network. Finally, HTSRP_Q is proposed to meet the QoS requirement when user want interactive or streaming packet service. This protocol will maximize the usage of resources of access layer based on the QoS parameters and process delay-sensitive traffic. Service classes are categorized into 5 types by the user request, such as conversational, streaming, high priority interactive, low priority interactive, and background class. It could be processed efficiently by the routing protocolstraffic model proposed in this paper. The proposed routing protocolstraffic model provides the increase of efficiency and stability of the next generation network thanks to the routing according to the characteristic of the specialized service categories.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1177-1184
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• 2014

An wired ship area network has functionality of remote control and autonomous management of various sensors and instruments embedded or boarded in a ship. For such environment, the DiffServ (Differentiated Services) realizes that the high-speed real-time flow with the higher priority has the guaranteed minimum data rate and is delivered faster. As a result of this DiffServ effect, the intelligent Ship Area Networks can be implemented. In this paper, an packet drop technique is proposed to outperform the previous RIO (RED In and Out) drop mechanism for DiffServ in ship area networks. the proposed packet drop technique does not manage the individual flows and divides them into several flow groups according to a criterion. And it guarantees the fairness between individual flows in the same QoS class through the group-based control. In simulation results of the proposed packet drop technique, the link utilization decreases than RIO. But it guarantees more data rates to DiffServ flows passing multiple bottleneck links.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.123-134
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• 2002

The requirement for QoS (Quality of Service) has become an important Issue as real-time or high bandwidth services are increasing, such as Internet Telephony, Internet broadcasting, and multimedia service etc. In order to guarantee the QoS of Internet application services, several approaches are being sought including IntServ (Integrated Service) DiffServ(Differentiated Srvices), and MPLS(Multi-Protocol Label Switching). In this paper, we describe the performance analysis of QoS guarantee mechanism using the DiffServ. To analyze how the DiffServ performance was affected by diverse input traffic models and the weight value in WFQ(Weighted Fair Queueing), we simulated and performed performance evaluation under a random, bursty, and self-similar input traffic models and for diverse input parameters. leased on the results of performance analysis, it was confirmed that significant difference exist in packet delay and loss depending on the input traffic models used. However, it was revealed that QoS guarantee is possible to the EF (expedited Forwarding) class and the service separation between RF and BE (Best Effort) classes may also be achieved. Next, we discussed the performance synthesis problem. (i. e. derived the conservation laws for a DiffServ networks, and analysed the performance variation and dynamic behavior based on the resource allocation (i.e., weight value) in WFQ.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.690-693
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• 2002

차세대 인터넷에서 DiffServ 네트워크는 서비스 품질(QoS: Quality of Service) 제공을 위한 확장성이 높은 구조를 제시하고 있다. 차세대 네트워크에서는 음성이나 비디오 전송 같은 많은 응용들을 지원하기 위하여 QoS 보장 서비스가 필요하다. 차세대 인터넷에서 QoS 제공을 위하여 RSVP(Resource Reservation Protocol), MPLS(Multi-Protocol Label Switching), DiffServ 및 QoS 라우팅 등의 기법이 개발되고 표준화되고 있다. 원격 교육 역시 주로 인터넷이 주도하고 있다는 면에서는 QoS의 문제를 피해 갈 수 없는 것이다. 그러나, 국내에서는 이러한 QoS 능력을 안전하게 제공하기 위한 기법에 대한 연구가 거의 없는 실정이다. 따라서, 본 논문에서는 QoS를 안전하게 제공하기 위한 보안 기법을 DiffServ 네트워크를 중심으로 제시하고 원격교육에 적용시의 문제들을 고려하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.133-135
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• 2003

본 논문에서는 IEEE 802.11 WLAN $^{[1]}$ 에서 QoS를 제공하기 위해 새로운 MAC­layer 구조를 제안한다. 주요 특징으로는 향후 Core Network의 모델로서 제시되고 있는 DiffServ 구조의 특징들을 WLAN에 적용하는 것을 들 수 있으며, 이를 통해 다양한 종류의 멀티미디어 트래픽에 적용될 End­to­end QoS를 보다 효율적 보장하고자 한다. DiffServ에서 제시되고 있는 Expedited. Assured forwarding과 일반적인 Best­effort traffic에 대한 service 차등화 기법을 WLAN에서 적용하기 위해 기존 MAC layer에서의 DCF, PCF 대신 EDWM(Extended DiffServ in WLAN MAC)이라는 새로운 MAC­layer 구조를 제시한다. 이를 통해 시간지연에 민감한 Expedited forwarding과 대역폭의 보장을 필요로 하는 Assured forwarding의 요구 사항(QoS)을 효율적으로 보장할 수 있다. 이에 더하여 기존의 인프라(infrastructure)인 IEEE 802.11b 환경의 DCF와 이를 통하여 service를 제공받는 일반적인 Best­effort traffic을 위한 backward compatibility 보장 방안을 제시한다.

• 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 Korea Information Processing Society Conference
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• 2002.11b
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• pp.1499-1502
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• 2002

DiffServ 망에서 완전한 QoS를 망 사용자에게 제공하기 위해서는 downstream 트래픽 뿐만 아니라, upstream 트래픽에 marking, policing 을 적용해 주어야 한다. 본 논문에서는 downstream 트래픽에만 QoS를 적용하는 단방향 트래픽 제어기법과, downstream및 upstream 트래픽에 QoS를 적용하는 양방향 QoS 서비스 기법을 비교하기 위하여, cisco 라우터를 이용하여 QoS 테스트베드를 구성하고, 성능을 측정 및 분석하였다.