• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.18-26
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• 2003

In this paper, we design and implement a QoS control function in the SIP-based VoIP system. As a network infrastructure for VoIP service, we select the Intserv over Diffserv architecture where the network resources are managed by a call admission control mechanism. The SIP protocol extended to support QoS signaling procedure is modulized to operate independently with the infrastructure. The performance of the QoS-enabled VoIP system is verified by experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.884-887
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• 2003

The standardization of QoS is recently becoming a major issue in VoIP market. This research is to look into the trend of the world and specification about QoS standadization, and present the needs for domestic VoIP QoS standardization.

• Convergence Security Journal
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• v.10 no.3
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• pp.69-75
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• 2010

At present, deterioration in service quality, which caused by increased network traffic from a lot of users in the same network, makes smooth communication service difficult. In this paper, we present policy-based QoS management system for VoIP service in order to supply smooth VoIP service to users. The presented system can guarantee quality of VoIP service even in huge traffic situation, and makes it possible to operate whole network in an efficient manner.

• Journal of Digital Contents Society
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• v.12 no.1
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• pp.85-94
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• 2011

QoS(Quality of Service) is defined as "The collective effect of service performance which determines the degree of satisfaction of a user of the service" by ITU-T Rec. E.800. While the use of VoIP(Voice Over Internet Protocol) has been widely implemented, persistent problems with QoS are a very important sue which needs to be solved. This research is finding the assignment of VoIP QoS to deduct how to manage the control system and presenting the QoS control process and framework under NGN(Next Generation Network) environment. The trial framework is the modeling of the QoS measurement metrics, instrument, equipment, method of measurement, the series of cycle & the methodology about analysis of the result of measurement. This research underlines that the vulnerability of the VoIP protocol in relation to its QoS can be guaranteed when the product quality and management are controlled and measured systematically. Especially it's very important time to maintain the research about VoIP QoS measurement and control because the big conversion of new network technology paradigm is now spreading. In addition, when the proposed method is applied, it can reduce an overall delay and can contribute to improved service quality, in relation to signal, voice processing, filtering more effectively.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.153-156
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• 2003

In this paper, we propose QoS guarantee system fur multi-functional VoIP end Terminal. This system guarantees low delay of voice data for Internet telephony in VoIP end terminal that has various kinds of Internet dependant application. QoS system we propose support low delay transmission in VoIP terminal interface.

• The Magazine of the IEIE
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• v.31 no.3
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• pp.66-77
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• 2004

Since telecommunication operators have commercialized VoIP services recently, it is important to provide quality of the call across networks. It is demanded that the same quality as PSTN provides should be supported in VoIP networks too. Several QoS solutions have been developed and proposed for VoIP service in many organizations for this purpose. In this paper, we explain several QoS Solutions for IP networks, and present the QoS architecture for Next Generation VoIP Networks, which is proposed by Multi-service Switching Forum.(omitted)

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.57-60
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• 2002

본 논문은 VoIP 시스템에서 적용 가능한 QoS 구조를 연구하였다. 현재 망 구조에서 실시간 트래픽은 최선형 트래픽과 구별이 되지 않아 보장받지 못한다. 따라서 본 논문에서는 QoS 구조를 위해 IETF에서 제안된 차등화서비스와 Intserv over Diffserv를 개관하였고, 이런 환경에서 VoIP 트래픽에 대한 품질을 보장하기 위한 QoS 구조를 연구하였다 또한, 측정기반 수락제어에 의해 기존망에 비해. 보다 좋은 품질을 제공할 수 있는 VoIP 시스템 구조도 함께 연구하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.106-108
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• 2003

인터넷의 확산과 발전으로 인한 서비스의 증가로 안정되고 고품질의 서비스를 위한 네트워크의 QoS 확보와 보장이 중요한 이슈로 대두되고 있다. 특히 VoIP와 같은 실시간 통신이 보장되어야 하고, 통화 품질이 수익 모델과 직결하는 서비스 및 장비에서는 QoS 지원이 매우 중요하다. 본 논문에서는 실시간 임베디드 리눅스 기술과 리눅스 커널에서 제공하는 라우팅 및 QoS 알고리즘을 적응하여 QoS 지원형 VoIP 게이트웨이를 설계 구현하고 성능을 측정 실험한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.280-282
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• 2003

본 연구에서는 HFC망에서 음성 통화품질에 영향을 주는 파라미터들에 대한 분석과 측정을 통해 VoIP의 특성을 파악하여 향후 본격적으로 이루어질 인터넷을 통한 음성 서비스 제공에 대비하였다 특히, VoIP QoS 기준의 정의는 QoS 파라미터의 분석을 토대로 한 lab 테스트와 HFC VoIP 서비스의 필드 측정을 병행하여 연구 결과에 대한 실질적 서비스 적용에 따르는 신뢰성을 높였다.

• Convergence Security Journal
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• v.8 no.4
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• pp.41-49
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• 2008

VoIP is a service that changes the analogue audio signal into a digital signal and then transfers the audio information to the users after configuring it as a packet; and it has an advantage of lower price than the existing voice call service and better extensibility. However, VoIP service has a system structure that, compared to the existing PSTN (Public Switched Telephone Network), has poor call quality and is vulnerable in the security aspect. To make up these problems, TLS service was introduced to enhance the security. In practical system, however, since QoS problem occurs, it is necessary to develop the VoIP security system that can satisfy QoS at the same time in the security aspect. In this paper, a user authentication VoIP system that can provide a service according to the security and the user through providing a differential service according to the approach of the users by adding AA server at the step of configuring the existing VoIP session is suggested. It was found that the proposed system of this study provides a quicker QoS than the TLS-added system at a similar level of security. Also, it is able to provide a variety of additional services by the different users.