• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.369-377
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• 2008

Today, Ethernet technology is rapidly developing to have a bandwidth of 10Gbps beyond 1Gbps. In such high-speed networks, the existing method that host CPU processes TCP/IP in the operating system causes numerous overheads. As a result of the overheads, user applications cannot get the enough computing power from the host CPU. To solve this problem, the TCP/IP Offload Engine(TOE) technology was emerged. TOE is a specialized NIC which processes the TCP/IP instead of the host CPU. In this paper, we implemented a high-performance, lightweight TCP/IP(HL-TCP) for the TOE and applied it to an embedded system. The HL-TCP supports existing fundamental TCP/IP functions; flow control, congestion control, retransmission, delayed ACK, processing out-of-order packets. And it was implemented to utilize Ethernet MAC's hardware features such as TCP segmentation offload(TSO), checksum offload(CSO) and interrupt coalescing. Also we eliminated the copy overhead from the host memory to the NIC memory when sending data and we implemented an efficient DMA mechanism for the TCP retransmission. The TOE using the HL-TCP has the CPU utilization of less than 6% and the bandwidth of 453Mbps.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.6
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• pp.296-305
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• 2005

TCP/IP, the most popular communication protocol, is processed on a host CPU in traditional computer systems and this imposes enormous loads on the host CPU. Recently TCP/IP Offload Engine (TOE) technology, which processes TCP/IP on a network adapter instead of the host CPU, becomes an important way to solve the problem. In this paper we analysed the structure of a TCP/IP protocol stack in the Linux operating system and important factors, which cause a lot of loads on the host CPU, by measuring the time spent on processing each function in the protocol stack. Based on these analyses, we propose a Hybrid TOE architecture, in which functions imposing much loads on the host CPU are implemented using hardware and other functions are implemented using software.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1607-1610
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• 2002

TCP/IP 의 성능을 향상 시키기 위하여 주로 커널 레벨에 구현되어 있는 TCP/IP 프로토콜 계층을 네트워크 인터페이스 카드로 이전시키는 기술을 TCP/IP offloading 기술이라고 한다. 본 논문은 최근의 TCP/IP offloading기술의 동향을 살펴보고 또한 Tcp/IP offloading 기술을 시스템에 적용할 때 고려해야 할 점등을 기술한다.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.7
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• pp.413-420
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• 2006

The speed of present-day network technology exceeds a gigabit and is developing rapidly. When using TCP/IP in these high-speed networks, a high load is incurred in processing TCP/IP protocol in a host CPU. To solve this problem, research has been carried out into TCP/IP Offload Engine (TOE). The TOE processes TCP/IP on a network adapter instead of using a host CPU; this reduces the processing burden on the host CPU. In this paper, we developed two software-based TOEs. One is the TOE implementation using an embedded Linux. The other is the TOE implementation using Lightweight TCP/IP (lwIP). The TOE using an embedded Linux did not have the bandwidth more than 62Mbps. To overcome the poor performance of the TOE using an embedded Linux, we ported the lwIP to the embedded system and enhanced the lwIP for the high performance. We eliminated the memory copy overhead of the lwIP. We added a delayed ACK and a TCP Segmentation Offload (TSO) features to the lwIP and modified the default parameters of the lwIP for large data transfer. With the aid of these modifications, the TOE using the modified lwIP shows a bandwidth of 194 Mbps.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.775-777
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• 2001

오늘날 매우 널리 사용되는 TCP/IP 프로토콜은 많은 보안적 흠을 가지고 있다. 시퀸스 번호를 스푸핑, 소스 번호를 스푸핑, 인증 공격 등 많은 류의 공격이 이런 홈을 통해서 행해지고 있다. 또한 근원적으로 패킷의 TCP헤더 필드의 포트 번호와 IP 헤더 필드의 주소 번호를 분석하여 포트번호와 IP번호를 알아내어 상대방을 공격한다. 이에 상대방으로부터 포트번호나 어드레스 번호를 은닉하거나 생략하여 전송하여 상대방이 패킷을 분석하기 어렵게 만들어 TCP/IP 패킷의 보호하고자 한다. 먼저 본 논문에서는 TCP 헤더의 Port field를 제거하기위한 수정된 TCP 연결설정의 메커니즘을 제시한다.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.42-52
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• 1998

This paper proposes an extended TCP/IP protocol, LAN/TCP, that can be used for the distributed soft real-time systems connected through the Ethernet-based local area network. Since LAN/TCP shows soft real-time performance with keeping compatibility and interoperability with the standard TCP/IP, the existing application software can be used without any modification. LAN/TCP also provides the periodic transmission mode(PTM) with which the periodical data collection and updating the control signals can be efficiently implemented with relatively small traffic overhead. This paper includes the computer simulation and experimental results of the proposed protocol.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.411-413
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• 2000

Internet망에서 mobile comupting에 대한 관심은 커져하고 있다. Mobile IP는 노드의 이동성을 지원하는 방법 중의 하나이다. 그렇지만 handoff 하는 과정에서 발생하는 패킷 손실 때문에 신뢰성의 문제가 발생한다. 게다가 mobile node(MN)와 foreign agent(FA)사이가 무선 링크인 경우 패킷 손실은 더욱 심각하다. TCP/IP는 고정된 네트워크에서 고안되어진 것이기 때문에 기존의 TCP/Mobile IP가 무선에는 부적합하다. 그러므로 본 논문에서 TCP/Mobile IP와 application사이에 midddleware로써 mobile agen(MA)를 사용하는 것을 제안했다. TCP mobile agent(TCP MA)을 여러 application에서 TCP 성능의 향상을 위해 제안했다. TCP MA는 FA와 MN를 위해 행동하고, 그리고 MN의 현재 위치에 상관없이 MN에 결과를 보낸다. 이러한 TCP MA는 handoff 동안에 발생하는 패킷 손실을 감소시킨다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.1
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• pp.35-45
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• 2004

In explosively increasing internet environments, information security is one of the most important consideration. Nowadays, various security solutions are used as such problems countermeasure; IDS, Firewall and VPN. However, basically internet has much vulnerability of protocol itself. Specially, it is possible to establish a covert channel using TCP/IP header fields such as identification, sequence number, acknowledge number, timestamp and so on. In this Paper, we focus cm the covert channels using identification field of IP header and the sequence number field of TCP header. To detect such covert channels, we used Support Vector Machine which has excellent performance in pattern classification problems. Our experiments showed that proposed method could discern the abnormal cases(including covert channels) from normal TCP/IP traffic using Support Vector Machine.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.99-104
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• 2010

We introduce Internet TCP/IP control system to monitor the traffic volume on the traffic network system. To check the traffic volume on traffic road, we use the traffic detector system shppe of circle or diamond or rectangular. Nevertheless we use traffic detector, we will use internet addressin TCP/IP system. If we use TCP/IP control system, we acquire many good point, we achive high sircurity and low costness traffic monitoring system coming difficulty and high level position. But internet system is very easy and low cost direction. Traffic control system is very more depending on the high techinquesion and very complexity. Therefore we introducing TCP/IP internet addressing control system schemetic point.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.5
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• pp.257-266
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• 2006

Recently TCP/IP Offload Engine (TOE) technology, which processes TCP/IP on a network adapter instead of the host CPU, has become an important approach to reduce TCP/IP processing overhead in the host CPU. There have been two approaches to implementing TOE: software TOE, in which TCP/IP is processed by an embedded processor on a network adapter; and hardware TOE, in which all TCP/IP functions are implemented by hardware. This paper proposes a hybrid TOE that combines software and hardware functions in the TOE. In the hybrid TOE, functions that cannot have guaranteed performance on an embedded processor because of heavy load are implemented by hardware. Other functions that do not impose as much load are implemented by software on embedded processors. The hybrid TOE guarantees network performance near that of hardware TOE and it has the advantage of flexibility, because it is easy to add new functions or offload upper-level protocols of TCP/IP. In this paper, we developed a prototype board with an FPGA and an ARM processor to implement a hybrid TOE prototype. We implemented the hardware modules on the FPGA and the software modules on the ARM processor. We also developed a coprocessing mechanism between the hardware and software modules. Experimental results proved that the hybrid TOE prototype can greatly reduce the load on a host CPU and we analyzed the effects of the coprocessing mechanism. Finally, we analyzed important features that are required to implement a complete hybrid TOE and we predict its performance.