• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.240-243
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• 2003

본 논문에서는 Agere Systems사의 네트워크 프로세서를 사용한 고성능 IP-DiffServ/IP-MPLS 시스템의 구조를 제안하고 성능을 분석한다. 제안한 시스템은 기가비트 이더넷 뿐만 아니라 ATM과 POS 등 다양한 인터페이스를 제공하며 코어 및 에지 라우터로서 MPLS LER 또는 LSR로의 역할을 수행한다. 성능분석은 OPNET을 사용하여 시스템을 모델링한 후 입력 트래픽에 대해서 DiffServ 클래스별 지연시간과 지연의 주된 원인을 분석한다. 그리고 이를 바탕으로 시스템의 성능을 극대화할수 있는 네트워크 프로세서의 최적 파라메터를 도출한다. 성능분석 결과, 시스템이 각 서비스 클래스에 대해서 원활한 서비스를 제공하기 위해서는 프리미엄 서비스에는 최고의 우선순위를 부여하여 큐에 데이터 블럭들이 찰 때 마다. 즉시 서비스해 주어야 한다는 것을 알 수 있었다. 그리고 트래픽이 특정 출구 라인카드로 몰리는 핫스팟이 발생할 경우 트래픽의 지연이 증가하게되는데 이 지연의 주요 원인은 출구 라인카드에서의 큐잉에 의한 것임을 알 수 있었다.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.364-367
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• 2008

Many different types of network equipments are deployed in a large-scale IP network. In this operating environment, network service providers suffer from difficulty in controlling various equipments simultaneously in case network faults happen in their overall or regional network due to physical link failure or abnormal traffic. This paper presents a policy-based methodology to control many different types of network equipments at the same time in abnormal cases. The key idea is that NMS(Network Management System) keeps vendor-neutral control policies in normal times and that when an abnormal case occurs in network, NMS transforms the selected policy into vendor-specific control commands and enforces them to various equipments simultaneously.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.7-16
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• 2012

In this paper we describe a VoIP transcript system which is able to record call conversation between counselor and customer in an IP contact center based on IP telephony environment. The transcript system, designed and implemented in this paper, uses packet sniffering to capture packets without imposing network overhead on overall system. It can decode H.323 and SIP which are used to setup call sessions in VoIP environment and captures voice data and record without any loss of contents. Implemented transcript system can be integrated with CTI system in that it can manage and record call more effectively. It is designed generically so that it is implemented both on Windows and Linux environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2405-2410
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• 2012

The 4th generation mobile communication system, LTE, does not support an additional core network to provide voice service, and it is merged into a packet network based on all IP. Although Voice service over LTE can be supported by VoIP, it will be provided by the existing 3G networks because of the discontinuity of LTE coverage. However, it is inevitable to adopt VoIP over LTE to provide high quality voice service. In this paper, we investigate the capacity of VoIP over LTE. Our results indicate that spectral efficiency can be significantly improved as channel bandwidth increases in terms of VoLTE capacity. In addition, we can achieve higher VoLTE capacity without decreasing control channel capacity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.683-690
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• 2003

In this paper we present a theoretical framework for the network design with delay QoS guarantee to a voice at the packet level. Especially, we propose a method for estimating the bandwidth at the ingress edge routers accommodating the voice connections and data sessions in the next-generation If network. First, we describe network architecture for VoIP (Voice over IP) services in the NGN (Next Generation Network). After that, we propose a procedure for dimensioning the bandwidth at the output port of a router that accommodates voice and data traffic using the non-preemptive queuing system with strict priority service scheme. Via numerical experiments we illustrate the implication of the proposition.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.82.4-82
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• 2001

Requirements for device control networks differ greatly from those of data (business) networks. Consequently, any control network which uses a filedbus protocol is, in general, different from If network protocol TCP/IP. One then needs to integrate both fieldbus protocol and TCP/IP to realize distributed control over IP network or internet. LonWorks technology provides networked intelligent I/O and controllers which make it a powerful, expandable solution. Connecting these remote Lon Works networks to the Internet can provide a powerful, integrated, distributed control system. This paper suggests a basic concept that be applied to distributed control over IP network or internet. Specially, Lonworks technology that used LonTalk protocol is reviewed as device network and ...

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1193-1200
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• 2000

A network topology has been an important factor for an efficient network management, but data collection for the network configuration has been done manually or semi automatically by a network administrator or an expert. Requirements to generate an intro-domain network topology ar usually either all IP addresses with subne $t^ernet mask or the network identification of all IP addresses. The amounts of traffic are generally high in the semi-automatic system due to using large number of low-level protocols and commands to get rather simple data. In this paper, we propose an algorithm which can be executed with only publicly available input. It can find all IP addresses as well as the network boundary of an intra-domain by using an intelligent method developed in this algorithm. The collected data will be used to draw a network map automatically by using a proposed network topology generation algorithm.hm.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.259-267
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• 2012

Internet telephony is an Internet service which supports voice telephone using VoIP technology on the IP-based Internet. It has some advantages in that voice telephone services can be accompanied with multimedia services such as video communication and messaging services. Recently, the introduction of smart phones has led to a growth in social networking services and thus, the research and development of Internet telephony has been actively progressed and has the potential to become a replacement for the telephone service that is currently being used. In this paper we designed and implemented an Internet telephony network system which is developed by using Asterisk and open source softwares. It is developed on the linux system and has some features such as VoIP telephony service between SIP phones, voice mail, and call recording. It also supports web-based functions such as SIP users and server system management that is implemented by Apache web server and PHP programs. Afterwards, this system will be applied as VoIP network base technology for small sized companies and organizations. It will paly a role for encouraging companies to use open source softwares.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.20-23
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• 2013

Recently for the transfer of large size video file between sites for high-definition craft editing used by broadcasting company the Public Network is used a lot. In the IP Public Network with QoS(Quality-of-Service) not guaranteed, degradation of performance has several causes. In this paper, we have analyzed the causes of low performance to transfer a large size HD video file in long distance, in order to maximize the effectiveness, the high efficiency network could be implemented enabling the highspeed of HD video file using the connection with networks between hosts through packet creation and multi-session of Parallel TCP. We survey the result of high speed transfer system and verify the efficient transfer method using Public IP Network for large HD video file transfer in broadcasting cooperation.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1235-1239
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• 2003

On the base of network frame and protocol system of Ethernet the networked sensing technology based on Ethernet is studied and the design principles of industrial Ethernet measurement of control system is put forward, and the general structure model is built in the paper. An eight-bit economical MCU scheme is proposed, and a general scheme of distributed intelligent networked measuring and control equipment based on TCP/IP is designed too. A compact TCP/IP protocol stack are successfully implemented in eight-bit MCU. With C51 program language, method of modularized programming is applied in soft design. The problem of in-system modifying measuring and control strategy of its system is solved successfully by assigning memory dynamically and saving parameter with EEPROM, and it makes the intelligent networked measurement and control system can explain and analyses control strategy from PC. Experiment result shows that, the research of intelligent networked measurement and control equipment and system base on TCP/IP is successful, with flexible network, convenient usage, and good commonality.