• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1330-1336
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• 2014

QoS techniques and transmitted in real-time communication with the advancement of technology a variety of applications and services are available these days, mobile devices bogeuphwa LTE technology to the development of multimedia services with high quality can be realized. In order to satisfy this condition simply with a router with an increased bandwidth expansion by considering the increase in the routing table of the network scalability problems included. Burst traffic data to be distributed according to the environment is to be centered. To do this, the destination -based routing method to transmit the current paper -based (Source routing) routing settings are required. In this paper, published by the IETF, IP switching system based on standardized protocol Label Switching Multi-Protocol Label Switching (MPLS) network by using the existing Best Effect is difficult to guarantee QoS for multimedia transmission in MPLS network environment using optimized QoS guarantees to transmit the multicast.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.9
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• pp.55-65
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• 2004

ATM was recommended by the ITU and ATM Forum as a means of transportation for B-ISDN. At this time, due to the comprehensive mature of ATM protocol, ATM has been adapted as the backbone system for carrying Internet traffi $c^{[1,2,3,4]}$. But major conceptsregarding the ATN protocol will be used on future technology. This paper presents preventive congestion control mechanisms for detecting HTR(Hard-To Reach) code in ATM systems, in particular for an improved HTR call registration method using network signaling information will discussed. In high speed circuit switching system environments, a fast HTR control mechanism is necessary. We present research results for improving HTR call registration and control methods using network signaling information and fuzzy control mechanisms. We concluded that it showed fast congestion avoidance mechanisms with a fewer system load maximized the efficiency of network resources by restricting ineffective machine attempts.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.287-298
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• 2001

Analysis of nonlinear behavior of prestressed concrete frame structures on PC is a time-consuming computing job if the problem size increase to a certain degree. Cluster system has emerged as one of promising computing environments due to its good extendibility, portability, and cost-effectiveness, comparing it with high-end work-stations or servers. In this paper, a parallel nonlinear analysis procedure of prestressed concrete frame structure is presented using cluster computing. Cluster system is configured with readily available pentium III class PCs under Win98 or Linux and fast ethernet. Parallel computing algorithms on element-wise processing parts including the calculation of stiffness matrix, element stresses and determination of material states, check of material failure and calculation of unbalanced loads are developed using MPL. Validity of the method is discussed through typical numerical examples. For the case of 4 node system, maximum speedup is 3.15 and 3.74 for Win98 and Linux, respectively. Important issues for the efficient use of cluster computing system based un PCs and ethernet are addressed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.235-245
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• 2005

In this paper, a simplified QoS model of MPLS-based backbone network. Conventional scheme proposed by IETF(IETF schem) is to embed a DiffServ model in MPLS network. However, this approach results in overall upgrade of MPLS system and so it is difficult to deploy this approach. Our proposed model, however, uses a Vidual Link which is a set of Label Switched Path(LSP) connected from an Ingress Label Edge Router(LER) to an Egress LER. In this model, Per-Hop-Behavior(PHB) is implemented only at each LSP in ingress LER and Core Label Switch Routers(LSRs) just guarantee each LSP's bandwidth, not service. This bandwidth guarantee service is fully provided by legacy MPLS model. Also we propose flow allocation mechanism and the flow distribution among LSPs of the virtual link by the flow according to the network status. To evaluate the simplified approach, the characteristics of the approach are compared logically with these of IETF's one through simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6B
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• pp.331-337
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• 2005

The optical Internet is considered as a feasible solution for transporting huge amount of traffic volume in the future Internet. Among optical switching technology for the optical Internet, OBS becomes one of the most promoting solution. Recently, a lebeled OBS(LOBS) architecture is considered for an efficient control on OBS network. Given that a data burst may contain few thousands of IP packets, a single loss of data burst results in a serious throughput degradation in LOBS network. In this paper, we improve the performance of LOBS network by introducing the burst congestion control mechanism. More specifically, the OBS router at the network core detects the network congestion by measuring the loss probability of burst control packet. The OBS router at the network edge reduces the burst generation according to the network condition repored by the OBS router at the network core. Through the simulations, it is shown that the proposed congestion control mechanism can reduce the burst loss probability and improve the LOBS network throughput.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7C
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• pp.677-684
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• 2002

Today's Internet does not have efficient traffic engineering mechanism to support QoS for the explosive increasing internet traffic such as various multimedia traffic. This functional shortage degrades prominently the quality of service, and makes it difficult to provide multi-media service and real-time service. Various technologies are under developed to solve these problems. IETF (Internet Engineering Task Force) developed the MPLS (Multi-Protocol Label Switching) technology that provides a good capabilities of traffic engineering and is independent layer 2 protocol, so MPLS is expected to be used in the Internet backbone network$\^$[1][2]/. The faults occurring in high-speed network such as MPLS, may cause massive data loss and degrade quality of service. So fast network restoration function is essential requirement. Because MPLS is independent to layer 2 protocol, the fault detection and reporting mechanism for restoration should also be independent to layer 2 protocol. In this paper, we present the experimental results of the MPLS OAM function for the performance monitoring and fault detection 'll'&'ll' notification, localization in MPLS network, based on the OPNET network simulator

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.437-445
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• 2000

More advanced and demanding applications, like videoconferencing, video on demand. distributed computing etc., have been devised thanks to the availability of enhanced network feature. Network technologies need to be enhanced to support these applications and to cope with the increasing number of users. Increasing the availability of network resources is just not enough to achieve this goal; scalable network architecture. increased packet forwarding capabilities, a wider range of services are all additional requirements. MOLS (multiprotocol label Switching) is one of the new networking techniques under standardization in the scientific community. In this paper, we analyze the performance of label switching in ATM networks. Simulation tests were performed. In this simulation, we set a simple network configuration and used internet traffic traces from NLANR as input traffic sources. The simulation results and analysis will be helpful in utilizing the functions of ATM switching and IP routing.

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.31-39
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• 2002

The VPN(Virtual Private Network) is a private network constructed logically on a public network infrastructure. There have been numerous studies to support the VPN services by using different technologies such as IP in IP, GRE, L2TP, MPLS and so on. Among these technologies, MPLS has shown many merits in aspects of QoS, security, and management, compared with other technologies. As an enhancement of the VPN that is controlled by MPLS PE(Provider Edge) routers, this paper presents the VPN controlled by MPLS CE(Customer Edge) routers. The functional architecture of the CE based VPN and operations of the CE routers are described along with the performance comparison of CE based MPLS VPN. It has been shown that the CE based VPN has more advantages than PE based VPN with respect to independency, scalability, security, and complexity.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.893-902
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• 2002

MPLS enables efficient explicit routing, and thus provides great advantages in supporting traffic engineering. Exploiting this capability, we Propose a load balancing scheme which deploys a multipath routing. It is named LBM (Load Balancing in MPLS networks), and targets at efficient network utilization as well as performance enhancement. LBM establishes multiple LSP (Label Switched Path)s between a pair of ingress-egress routers, and distributes traffic over these LSPs at the new level. Its routing decision is based on both the length and the utilization of the paths. In order to enhance the efficiency of a link usage, a link is limited to be used by shorter paths as its utilization becomes higher Longer paths are considered to be candidate alternative paths as the utilization of shorter paths becomes higher. Simulation experiments are performed in order to compare the performance of LBM to that of static shortest path only scheme as well as the other representative dynamic multipath traffic distribution approaches. The simulation results show that LBM outperforms the compared approaches, and the performance gain is more significant when the traffic distribution among the ingress-egress pairs is non-uniform.

• Journal of Korea Multimedia Society
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• v.3 no.2
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• pp.148-156
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• 2000

This paper proposed that an MPLS-based VPN using next-generation If switches and appropriate set of traffic engineering algorithms is the best way to implement QoS-capable IP VPNs. While ATM-based solution would not rely scalable the number of connections becomes too large, MPLS-based VPNs’ efficiency could be confirmed network delay time through performance evaluation. And we evaluated the performance about the If VPN based on proposed MPLS, at the result of evaluation. We figured out that delay increased more slowly in case of VPN based on MPLS comparing with the VPN based on ATM which has rapid delay increasement. Therefore we confirm that the VPN based on MPLS has high speed of packet processing and high degree of network efficiency through the performance evaluation.