• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.63-69
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• 2006

Problems like poor security, transfer delay or packet loss occur while building network systems that are applied with TCP/TP integrate with data network systems. To solve this problem, this paper proposes the Separated Ethernet, which can give priority to the system, and by using the OPNET Modeler simulator, we will verify its performances.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.691-698
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• 2006

TCP/IP Offload Engine (TOE) is a technology that processes TCP/IP on a network adapter instead of a host CPU to reduce protocol processing overhead from the host CPU. There have been some approaches to implementing TOE: software TOE based on an embedded processor; hardware TOE based on ASIC implementation; and hybrid TOE in which software and hardware functions are combined. In this paper, we designed software modules and hardware modules for a hybrid TOE on an FPGA that had two processor cores. Software modules are based on the embedded Linux. Hardware modules are for data transmission (TX) and reception (RX). One core controls the TX path and the other controls the RX path of the Linux. This TX/RX path separation mechanism can reduce task switching overheads between processes and overcome poor performance of single embedded processor. Hardware modules deal with creating headers for outgoing packets, processing headers of incoming packets, and fetching or storing data from or to the host memory by DMA. These can make it possible to improve the performance of data transmission and reception. We proved performance of the TOE with separated transmission and reception paths by performing experiments with a TOE network adapter that was equipped with the FPGA having processor cores.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.617-632
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• 2009

In this paper we propose a technique of implementing the reconfigurable network protocol stack that allows for partitioning network protocol functions into software and hardware tasks on a SoC (System on Chip) platform. Additionally, we present a method that guarantees the deadline of both an individual task and messages exchanging among tasks in order to meet the deadline of real-time multimedia and networking services. The proposed real-time message exchange method guarantees the deadline of messages generated by multimedia services that are required to meet the real-time properties of multimedia applications. After implementing the networking functions of TCP/IP protocol suite into hardware and software tasks, we verify and validate their performance on the SoC platform. Experimental results indicate that the proposed technique improves the performance of TCP/IP protocol suit as well as application service satisfaction in application-specific real-time.

• Convergence Security Journal
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• v.7 no.4
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• pp.1-8
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• 2007

Currently, the needs of open standard and integrated network, and also applications of Ethernet network based system are increasing. By applying and expanding TCP/IP based network technology from high to low control level, factory automation application has been implemented, and thus integrated factory automation system has been accomplished, which is directly interoperable between high level management program and DB system. This paper proposes a communication control device which is based on Ethernet/IP standard system for factory automation. The proposed system is workable in the environment of a network system, which is based on CIP standard interface technology. The proposed system can also contribute to improve data communication characteristics.

• Journal of Mechanical Science and Technology
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• v.16 no.8
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• pp.1033-1038
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• 2002

Genetic alsorithm (GA) , compared to the gradient-based optimization, has advantages of convergence to a global optimized solution. The genetic algorithm requires so many number of analyses that may cause high computational cost for genetic search. This paper proposes a personal computer network programming based on TCP/IP protocol and client-server model using socket, to improve processing speed of the genetic algorithm for optimization of composite laminated structures. By distributed processing for the generated population, improvement in processing speed has been obtained. Consequently, usage of network-based genetic algorithm with the faster network communication speed will be a very valuable tool for the discrete optimization of large scale and complex structures requiring high computational cost.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2B
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• pp.263-271
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• 2004

In this paper, we proposed a new buffer management algorithm using perVC-Queuing discipline. Proposed algorithm uses service rate estimation and assigns dynamic perVC threshold to each VCs. Service rate estimation and dynamic perVC threshold combined with global threshold provide nearly optimal throughput and improve fairness performance of network resource among GFR VCs as well as guarantee MCR of all VCs. From simulation results, we demonstrate the proposed scheme fulfills the requirement of GFR service as well as improves the TCP throughput.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.2
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• pp.114-124
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• 2009

In this paper, we propose a practical TCP friendly rate control scheme that considers the minimum channel bandwidth of the network when transporting SVC (scalable video coding) video over IP netowrks such as Internet. RTP and RTCP is mainly designed for use with UDP (User Datagram Protocol) for real-time video transport over the Internet. TCP-friendly rate control was proposed to satisfy the demands of multimedia applications while being reasonably fair when competing for bandwidth with conventional TCP applications. However the rate control model of the conventional TCP-friendly rate control scheme does not consider the minimum channel bandwidth of the network. Thus the estimated channel bandwidth by the conventional rate control model might be quite different from the real channel bandwidth when the packet loss ratio of the network is very large. In this paper, we propose a modified TCP-friendly rate control scheme that considers the minimum channel bandwidth of the network. Based on the modified TCP-friendly rate control, we assign the minimum channel bandwidth to the base layer bitstream of SVC video, and remaining available bandwidth is allocated to the enhancement layer of SVC video for the TCP friendly scalable video transmission. It is shown by simulations that the modified TCP-friendly rate control scheme can be effectively used for a wider range of controlled bit rates depending on the packet loss ratio than the conventional TCP-friendly control scheme. Furthermore, the effectiveness of the proposed scheme in terms of objective video quality is proved by comparing PSNR performance with the conventional scheme.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.138-141
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• 2010

Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. we show that a multiple time scale TCP endows the underlying feedback control with proactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of the three traffic control dimensions-tracking ability, connection duration, and fairness-on performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.858-861
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• 2002

As mobile devices have become widely popular, users want to use devices not only wireless but also mobile. Mobile IP is used to support mobility on TCP/IP network. In mobile IP, when a terminal changes location, the terminal requests a registration to Home Agent through Foreign Agent in new location. After the request is accepted by Home Agent, the terminal can use network again. We call this process as handoff. In mobile n, handoff provokes loss of data packets and network delay. In this paper, we describe the implementation of pre-registration which is a solution of the handoff problems. Pre-registration improves the traditional handoff mechanism by requesting registration through current FA before location change. This muchanism can decrease packet loss and network delay.

• The KIPS Transactions:PartC
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• v.13C no.3 s.106
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• pp.283-294
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• 2006

Hostile network traffic is often different from normal traffic in ways that can be distinguished without knowing the exact nature of the attack. In this paper, we propose a new anomaly detection method using inbound network traffic distributions. For this purpose, we first characterize the traffic of a real campus network by the distributions of IP protocols, packet length, destination IP/port addresses, TTL value, TCP SYN packet, and fragment packet. And then we introduce the concept of entropy to transform the obtained baseline traffic distributions into manageable values. Finally, we can detect the anomalies by the difference of entropies between the current and baseline distributions. In particular, we apply the well-known denial-of-service attacks to a real campus network and show the experimental results.