• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1722-1727
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• 2011

The Korea Army are developing the TICN(Tactical Information Communication Network) which is the next army tactical communication system. The TICN tactical backbone's ability is very important. So analysis of the standard protocol for the data transmission guarantee are obliged. For the TICN tactical backbone, previous paper analysed routing protocol efficiency index and compared to superiority of the OSPF and IS-IS protocols in the tactical environment and conclusively IS-IS protocol was more suitable for TICN backbone routing protocol. And We got the result that It could improve the performance of IS-IS protocol as a TICN tactical backbone protocol under the tactical environments by adjusting some time parameters of IS-IS protocol. This paper modified and designed the IS-IS protocol in order to support the QoS strategies of TICN and analyzed it's adaptability through simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.645-653
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• 2016

The terrestrial wireless backbone network and satellite communications system have been independently developed depending on their own purposes and operational concepts, which results in different characteristics in terms of network architecture and routing protocol operation. In this paper, we propose a method for structurally integrating them in consideration of routing mechanism in an autonomous system. Our approach is that the routers of satellite network operate the OSPF in PTP mode on their interfaces connected to the routers of terrestrial wireless backbone network with grid connectivity, whereas the OSPF in satellite network whose topology is of hub-spoke type runs in NBMA mode. We perform some simulations to verify that the satellite communications system can be integrated and interwork with the terrestrial wireless backbone network by our proposed approach. From simulation results, it is also found that the increases of network convergence time and routing overhead are acceptable.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.13-22
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• 2008

This paper gives reviews on current research status in telecommunication network design. Two problems are identified as major research issues. One is the WDM network design problem, where traffic grooming, virtual topology design and routing and wavelength assignment problems are considered. The other is the OSPF weight setting problem which was proposed as a practical method to implement traffic engineering capability in IP networks. After presenting surveys on those problems, we discuss potential challenging research issues in telecommunication network design.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.559-566
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• 2016

Software defined network (SDN) can effectively improve the performance of traffic engineering and will be widely used in backbone networks. Therefore, new energy-saving schemes must take SDN into consideration; this action is extremely important owing to the rapidly increasing energy consumption in telecom and Internet service provider (ISP) networks. Meanwhile, the introduction of SDN in current networks must be incremental in most cases, for technical and economic reasons. During this period, operators must manage hybrid networks in which SDN and traditional protocols coexist. In this study, we investigate the energy-efficient traffic engineering problem in hybrid SDN/Internet protocol (IP) networks. First, we formulate the mathematical optimization model considering the SDN/IP hybrid routing mode. The problem is NP-hard; therefore, we propose a fast heuristic algorithm named hybrid energy-aware traffic engineering (HEATE) as a solution. In our proposed HEATE algorithm, the IP routers perform shortest-path routing by using distributed open shortest path first (OSPF) link weight optimization. The SDNs perform multipath routing with traffic-flow splitting managed by the global SDN controller. The HEATE algorithm determines the optimal setting for the OSPF link weight and the splitting ratio of SDNs. Thus, the traffic flow is aggregated onto partial links, and the underutilized links can be turned off to save energy. Based on computer simulation results, we demonstrate that our algorithm achieves a significant improvement in energy efficiency in hybrid SDN/IP networks.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.18-22
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• 2014

Satellite communications consist of communications between base stations of the ground and satellites. For efficient satellite communications, ground networks should be organically utilized. Grid networks are frequently used in and outside the country for wireless communications. The performance of wireless communications is determined by mobility, topography, and jamming signals. Therefore, continuous studies of grid networks are necessary for the utilization of next period satellite networks. Since military communications are used based on wireless systems, they can be considered as a sample of utilization of grid networks. Therefore, this paper presented the results of simulations conducted for the improvement of the performance of the grid networks used in military communications that employing the OSPF, a popular routing protocol for military applications. First we investigate the effects of changing the bit error rate (BER) and number of routers. Then we discuss the effects of maximum segment size (MSS) on network behavior and stability. In this way, we can determine the appropriate MSS for a grid network under various values of BER and number of routers. Such results can be also applied to commercial grid network evaluations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.572-575
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• 2009

With the advent of integration environment of broadcasting and communication, IPTV has been widely used. It provides services such as information, movie contents and broadcasting through TV using super-high speed networks. Developments of Wireless LAN and IP network technology create various and fusional services such as IPTV, VoIP that are based on IP network. The development of Wireless LAN is very important in IPTV network field which requires the best quality of service on the security, QoS and bandwidth. In this Paper, We configure the experimental network in its RIP and OSPF environment to test the Video Quality of IPTV in Wireless LAN. We measure and evaluate broadcasting quality by using PSNR to show the corelation of Routing Protocols in Wireless LAN in which how they affect to the IPTV real-time Video Quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.5
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• pp.326-328
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• 2014

In this paper we propose an efficient algorithm for LSA(Link State Advertisements) flooding. Link state routing protocols have been widely adopted in wired networks. When link state change occurs, a LSA is flooded into the whole network. The overhead of LSA flooding may be a big problem in wireless networks because their link states can be changed frequently. We propose an efficient flooding method that optimizes the flooding processes in wireless networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12A
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• pp.1879-1886
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• 2000

향후 컴퓨터 망은 버스트한 트래픽이 주종을 이룬다. OSPF 또는 RIP와 같은 최단경로 라우팅 프로토콜은 단일 경로의 라우팅으로 인해 병목을 초래하는 단점이 존재한다. 따라서, 발, 착신 노드간에 선택된 단일경로는 높은 정체를 유발하는 반면 다른 다수의 경로는 낮은 활용도를 나타낸다. 따라서, 본 고에서는 제한된 난수(bounded randomization)를 통해 전체 망에서 데이터 트래픽을 분산하는 라우팅 방법을 제안한다. 이 방법은 병목을 제거함으로서 망의 성능을 향상시킨다. 각각의 데이터 메시지는 원천 s에서 목적지 d로 전송되며 본 고에서 라우팅 프로토콜은 선택되는 망노드 집합의 a로부터 중간 노드 e를 무작위로 선택하고 데이터 메시지를 s에서 e까지의 최단경로로 라우팅을 한다. 이어서, e에서 d까지의 최단경로를 통해 데이터 메시지를 라우팅한다. 이는 각각의 원천과 목적지간 대역폭의 효율성을 증가시킨다. 본 고의 실험결과는 전체의 망에서 제안된 트래픽 분산 라우팅 프로토콜에서 기대치의 처리량(throughput), 메시지 손실과 메시지 지연에 따른 망성능 향상을 증명하고 있다. 그리고, 본 고의 알고리즘의 구현은 단지 최단경로 라우팅 프로토콜의 단순한 확장으로 가능하다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1115-1118
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• 2002

최근 해킹 기술이 다양화되고, 사용하기 손쉬운 해킹 툴들이 개발되고 확산되면서, 라우팅 프로토콜의 취약점을 이용한 해킹 사례 또한 급증하고 있다. 이는 RIP, OSPF, BGP 등의 초기 인터넷 라우팅 프로토콜이 보안에 대한 고려 없이 설계되어서, 이에 대한 간단한 패스워드 및 MD5 인증 등의 보완책으로 등장한 RIPv2, OSPFv2 BGPv4 등도 그 취약성을 계승하고 있기 때문이다. 따라서 현재의 전반적인 라우팅 프로토콜에 문제점을 파악하고, 이를 해결하기 위한 연구가 필요하다. 본 논문에서는 이러한 취약사항들을 이용한 위협 모델들을 분석하고, 이들 위협으로부터 미리 방비할 수 있도록 진단할 수 있는 시스템을 설계 및 구현에 대한 방법을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1004-1007
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• 2010

본 논문은 대용량을 요구하는 멀티미디어와 같은 스트리밍 서비스등 이에 관한 품질을 사용자의 요구에 따라 빠르게 요구 대역폭을 할당하고 보장하기 위한 광대역폭 기반의 응용지원을 위한 DCN(Dynamic Circuit Network)을 구축 및 검증하는 내용을 기술 하였다. 이를 위해 GMPLS, RSVP, OSPF등의 기술을 기반으로 2계층의 LSP를 동적으로 할당할 수 있게 하였으며, WBUI(Web-based User Interface)를 통해 사용자의 요구를 받아서 서비스를 제공할 수 있게 하였고, Iperf를 통해 요구 대역폭 할당과 보장을 검증한다.