• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1117-1120
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• 2000

인터넷 소프트웨어 개발자는 인터넷 보안 소프트웨어, 네트워크 실습 교육용 소프트웨어 등의 다양한 서비스 개발을 위해, 데이터 링크 계층의 프레임에 직접 접근하는 방법을 요구한다. 이러한 개발자를 위해, Windows 2000은 사용자 계층에서 인터넷 관련 네트워크 자원에 접근할 수 있는 Winsock, NPP, Internet Protocol Helper API를 지원한다. 하지만, 개발자가 이러한 API, 특히 Winsock API를 통해 직접 데이터 링크 계층의 프레임에 접근하는 데에는 한계가 있다. 따라서, 본 논문에서는 NDIS Library를 이용하여 일반 개발자가 손쉽게 데이터 링크 계층의 프레임에 접근할 수 있는 packet driver API를 설계하였다. API를 구성하는 각 클래스는 계층적 구조로 설계하였으며 Visual C++를 사용하여 구현하였다.

• Journal of Communications and Networks
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• v.7 no.1
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• pp.1-12
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• 2005

Ethernet is being deployed in metropolitan area networks (MANs) as a lower-cost alternative to SONET-based infrastructures. MANs are usually required to support common communication services, such as voice and frame relay, based on legacy synchronous TDM technology in addition to asynchronous packet data transport. This paper addresses the clock synchronization problem that arises when transporting synchronous services over an asynchronous packet infrastructure, such as Ethernet. A novel algorithm for clock synchronization is presented combining time-stamp methods used in the network time protocol (NTP) with signal processing techniques applied to measured packet interarrival times. The algorithm achieves the frequency accuracy, stability, low drift, holdover performance, and rapid convergence required for viable emulation of TDM circuit services over Ethernet.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.203-216
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• 2019

The nature of wireless transmission has made wireless sensor networks defenseless against various attacks. This paper presents warning message counter method (WMC) to detect blackhole attack, grayhole attack and sinkhole attack in wireless sensor networks. The objective of these attackers are, to draw the nearby network traffic by false routing information and disrupt the network operation through dropping all the received packets (blackhole attack), selectively dropping the received packets (grayhole and sinkhole attack) and modifying the content of the packet (sinkhole attack). We have also attempted light weighted symmetric key cryptography to find data modification by the sinkhole node. Simulation results shows that, WMC detects sinkhole attack, blackhole attack and grayhole attack with less false positive 8% and less false negative 6%.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.287-289
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• 2013

Fast Handover for Proxy Mobile IPv6 (FPMIPv6), a protocol described in RFC 5949, is used to reduce handover latency and minimize packet loss problem occuring in the Proxy Mobile IPv6 (PMIPv6) protocol. However, during the study of implementing FPMIPv6, we found the Out-of-Order Packet (OoOP) problem that occurs in the experiment of FPMIPv6. Since the OoOP is an issue that affects significantly to QoS of the network, in this paper, we analyze the OoOP problem by using network model. The analysis conducts the cause of occurring OoOP problem due to there exist two paths for data transmitted from Correspondent Node (CN) to MN in FPMIPv6.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.163-172
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• 2003

Proposed in this paper is an authentication mechanism for multimedia streaming data in the Intemet multicast environment. The multicast authentication mechanism is coupled with the packet-level forward error correction code which has been recently applied for a reliable multicast transport transmission. Associated with this, Reed-Solomon erasure code is chosen for tolerating packet loss so that each of the received packets can be authenticated independently of the lost packets.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.641-646
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• 2003

Packet processing speed of routers as well as transmission speed of physical links gives a great effect on IP packet transfer rate in Internet. The router forwards a packet after determining the next hop to the packet's destination. IP address lookup is a main design issue for high performance routers. In this paper, we propose a partitioned compressed-trie for speeding-up IP address lookup algorithms based on tie data structure by exploiting path compression. In the ,proposed scheme, IP prefixes are divided into several compressed-tries and lookup is performed on only one partitioned compressed-trie. Memory access time for IP address lookup is lessen due to compression technique and memory required for maintaining partition does not increased.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11
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• pp.2900-2910
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• 1999

Since its introduction in the early 1990s, the quick growth of the world Wide Web (WWW) traffic raises the question whether past LAN packet traces still reflect the current situation or whether they have become obsolete. For this study, several LAN packet traces were obtained by monitoring the LAN of a typical academic environment. The tools for monitoring the network were a stand-alone HP LAN Protocol Analyzer as well as the free-ware software tool tcpdump. Our main focus was placed on acquiring a low-level overview of the LAN traffic. Thus, we could determine what protocols were mainly used and how the packet sizes were distributed. In particular, we were interested in establishing the amount of WWW traffic on the LAN, and what MIME-Types this traffic is subdivided into. Our results indicate that in a typical academic environment such as ours, conventional sources of LAN traffic such as NFS are still predominant, whereas WWW traffic plays a rather marginal role. Furthermore, we verified that a large portion of the network packets contains little or no data at all, while another significant portion of the packets has sizes around the MTU. Consequently, research in the networking field has to direct its focus on issues beyond the WWW.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.53-60
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• 2006

As it has been continuously increased the volume of traffic over Internet, it is hard for a network traffic monitoring system to analysis every packet in a real-time manner. While it is increased usage of applications which are dynamically allocated port number such as peer-to-peer(P2P), steaming media, messengers, users want to analyze traffic data generated from them. This high level analysis of each packet needs more processing time. This paper proposes to introduce load shedder for limiting the number of packets. After it determines what application generates a selected packet, the packet is analyzed with a defined application protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.4
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• pp.729-739
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• 1994

In a centralized spread-spectrum packet radio network, a random assignment -transmitter-based spreading code protocol(RA-T) is proposed which permits the contention mode only in the trasmission of a preamble while avoiding collision during the data packet transmission by assigning near-orthogonal spreading codes to each user. Compared to the conventional transmitter-based code scheme, this scheme allows reduction in receiver complexity when only a small number of distinct spreading codes are employed for the preamble transmission. Throughout theoretical and simulation results, it is shown that the use of the RA-T scheme with just two or three distinct codes for the preamble packet achieves most of the performance gain.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.328-333
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• 2004

SK Telecom은 2000년 10월 세계 최초로 기존 IS-95A/B망에서 지원하였던 속도인 14.4Kbps나 56Kbps 보다 훨씬 빠른 최고 144Kbps로 무선인터넷이 가능한 CDMA2000 IX를 상용화 하였다. 또한, 2002년 1월에는 CDMA2000 IX보다 15배 이상 빠른 최대 2.4Mbps가 가능한 동기식 3세대 망인 CDMA2000 IxEV-DO를 세계 최초로 상용화 하였다. 이러한 초고속 무선 인터넷 서비스를 위해서 패킷 데이터 처리에 필수적인 PDSN(Packet Data Serving Node), HA(Home Agent), AAA(Authentication, Authorization and Accounting) 등의 노드들로 구성된 Packet Core Network(이하 PCN)이 도입되었으며, 이에 대한 운용 및 관리 방안이 중요한 issue로 등장하였다. 본 논문에서는 기존의 음성 서비스 관리를 위한 망관리 시스템(Network Management System)과는 다른 개념으로 관리되어야 할 패킷 서비스를 위한 NMS 구축 방안을 제시하고, 필수적인 관리 정보 및 서비스 관리를 위한 방향을 제시한다.