• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.551-558
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• 2005

In this paper, we implement the fast handovers for mobile IPv6 (FMIPv6) on Linux system. Due to its dependency on operations in layer-2 (L2), we have added some functions into the network driver to generate triggers as the mobile node moves. We design and implement the FMIPv6 functions divided into two parts as an access router and a mobile node. We compare the packet loss and delay of the FMIPv6 implementation during the handover period with those of the MIPv6 and investigate the performance improvement.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.367-374
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• 2002

IPsec offers not odd Internet security service such as Internet secure communication and authentication but also the safe key exchange and anti-replay attack mechanism. Recently IPsec is implemented on the various operating systems. But there is no existing tool that checks the servers, which provide IPsec services, work properly and provide their network security services well. In this paper, we design and implement the rule based security evaluation system for IPsec engine. This system operated on Windows and UNX platform. We developed the system using Java and C language.

• Journal of KIISE:Information Networking
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• v.37 no.6
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• pp.477-482
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• 2010

Recently, advanced Internet applications such as Internet telephone, multimedia streaming, and file sharing have appeared. Especially, P2P or web-based file sharing applications have been notorious for their illegal usage of contents and massive traffic consumption by a few users. This paper presents a novel method to identify the P2P or web-based file names with traffic monitoring. For this purpose, we have utilized the Korean decoding method on the IP packet payload. From experiments, we have shown that the file names requested by BitTorrent, Clubbox, and Tple applications could be correctly identified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.916-919
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• 2003

Reliable multicast data transmission in a 1:N environment needs more sophisticated error control mechanism than that of in 1:1 environment due to ACK implosion and duplicated retransmission. Although there have been many related research on error control in reliable multicast, real implemented protocols are rare. As one of the reliable multicast transport protocols, ECTP is selected as an international standard reliable multicast protocol by ITU-T and ISO and implemented on RedHat 7.2 machine by us. In this paper, we evaluate the performance of the error control mechanism in the respect of throughput and generated control packet numbers with a real implementation code. From the results, it is concluded that the suitable values of error control parameters can be obtained from the local group size and network environments.

• International Journal of Quality Innovation
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• v.10 no.1
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• pp.115-126
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• 2009

Video transmission effectiveness in the Ad Hoc network is becoming important recently, if different routing protocols are applied. Some researchers conclude that the reactive protocols are better for file transfer protocol (FTP) and constant bit rate (CBR) or hypertext transfer protocol (HTTP) transmission in an Ad Hoc wireless network but the performance report of video transmission is not much. This study adopts Qualnet (Network Simulator) as a simulation tool for environmental designing and performance testing, and employs an experimental design with eight groups. Our experiment shows that: (1) The performance of AODV (reactive) protocol is better than DSDV, ZRP and DSR when the transmission load has only one video stream; (2) Proactive (DSDV) and Hybrid protocols (ZRP) are better for a smaller Ad Hoc network when it transmits a video stream with some applications (VoIP, FTP and CBR). We conclude that packet loss rate is sensitive to the quality of video transmission and it has negative relationship with Peak Signal-to-Noise Ratio (PSNR) value. In addition, our experiment also shows that PSNR is a simple Metric for the performance evaluation of video transmission.

• Convergence Security Journal
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• v.5 no.2
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• pp.1-8
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• 2005

Network event analysis gives useful information on the network status that helps protect attacks. It involves finding sets of frequently used packet information such as IP addresses and requires real-time processing by its nature. Apriori algorithm used for data mining can be applied to find frequent item sets, but is not suitable for analyzing network events on real-time due to the high usage of CPU and memory and thus low processing speed. This paper develops a network event audit module by applying association rules to network events using a new algorithm instead of Apriori algorithm. Test results show that the application of the new algorithm gives drastically low usage of both CPU and memory for network event analysis compared with existing Apriori algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.9
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• pp.358-365
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• 2003

To support Internet traffic efficiently over ATM networks, Guaranteed Frame Rate(GFR) has been proposed in the ATM Forum. GFR provides minimum rate guarantees to VCs and allows any excess bandwidth in the network to be shared among the contending VCs in a fair manner. In this paper, we proposed a new fuzzy logic based buffer management algorithm that provides MCR guarantee and fair sharing to GFR VCs. A key feature of proposed algorithm is its ability to accept or drop a new incoming packet dynamically based on buffer condition and load ratio of VCs. This is achieved by using fuzzy logic controller for the production of a drop factor. Simulation results show that proposed scheme significantly improves fairness and TCP throughput compared with previous schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.109-112
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• 2005

As the degree of use of network is increasing the need for building the basic of the stable network service is being needed a lot. Also the engineers require the traffic control for the best application and management and bandwidth management urgently. To solve these problems, there were no other ways of increasing the bandwidth of lines until now. However, this solution has the limit that the cost is too high and the traffic problem is growing continuously. On this study, it is suggested that through the planning the wired /wireless combination network design offering the service of QoS, Multicast, Mobile, realtime multimedia traffic delay without packet loss will be dealth with.

• Journal of IKEEE
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• v.22 no.4
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• pp.1147-1151
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• 2018

As personal users create and share lots of contents at any time and any places, new networking architecture such as content centric networking (CCN) has emerged. CCN utilizes content name as a packet identifier, not address. However, current CCN has a limitation for content source mobility management. The movement of content sources cause long delivery latency and long service disruption. To solve that, a hierarchical mobility management was was proposed. However, the hierarchical mobility management scheme has still the loss of interest packets and long handoff latency. So, this paper presents the hybrid hierarchical mobility management in mobile CCN environements to reduce both the loss rate of interest packets and the handoff latency. It is shown from the performance evaluations shows that the proposed scheme provides low loss rate of control message.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.212-218
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• 2021

Low-power and Lossy Networks (LLNs) have become the common network infrastructure for a wide scope of Internet of Things (IoT) applications. For efficient routing in LLNs, IETF provides a standard solution, namely the IPv6 Routing Protocol for LLNs (RPL). It enables effective interconnectivity with IP networks and flexibly can meet the different application requirements of IoT deployments. However, it still suffers from different open issues, particularly in large-scale setups. These include the node unreachability problem which leads to increasing routing losses at RPL sink nodes. It is a result of the event of memory overflow at LLNs devices due to their limited hardware capabilities. Although this can be alleviated by the establishment of multi-sink topologies, RPL still lacks the support for effective load balancing among multiple sinks. In this paper, we address the need for an efficient multi-sink load balancing solution to enhance the performance of PRL in large-scale scenarios and alleviate the node unreachability problem. We propose a new RPL objective function, Multi-Sink Load Balancing Objective Function (MSLBOF), and introduce the Memory Utilization metrics. MSLBOF enables each RPL node to perform optimal sink selection in a way that insure better memory utilization and effective load balancing. Evaluation results demonstrate the efficiency of MSLBOF in decreasing packet loss and enhancing network stability, compared to MRHOF in standard RPL.