• Journal of Digital Contents Society
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• v.2 no.1
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• pp.31-40
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• 2001

Currently there are many standards of network management. They are: SNMP(Simple Network Management Protocol - for Internet management), CMIP(Common Management Information Protocol - standardized by ITU-T and ISO), RMON(Remote network MONitoring - for distributed management of the LAN segment), and so on. Especially RMON has created the many concerns in order to manage subnetworks of a large network, but it has negative aspects. For instance, routers or hubs with RMON capability are expensive to a network manager because of adding heavy management cost. Moreover it imposes a heavier burden on network manager, because it must use a network management tool which will be additionally needed with RMON device. This paper proposes a model of PC based RMON Agent system. The RMON Agent system monitors the traffic on LAN segment through the use of a Virtual Device Driver(VxD), based on PC. In term of cost this model will replace the expensive RMON device, and eventually enable a network manager to manage LAN segment more efficiently, due to reduced cost.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1001-1004
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• 2000

본 논문에서는 여러 개의 Lan 세그먼트를 관리하며 패킷의 분석과 이용현황 등을 비교, 분석하기 쉽게 해주는 Lan 모니터링 매니저 시스템과 각 세그먼트별로 패킷을 수집하는 LAN 모니터링 에이전트를 설계 및 구현하였다. 네트워크의 규모가 커지고 관리를 요하는 장비가 증가함에 따라 기존의 NMS 로는 관리에 있어 한계를 보여왔다. 이에 Lan 세그먼트단위의 관리를 하는 RMON 에이전트의 필요성이 대두되는데, 이 또한 여러 Lan 세그먼트를 관리하기 위해 RMON 장비를 세그먼트마다 탑재해야 하는 등 비용과 관리의 어려움이 있다. 따라서 본 논문에서는 소프트웨어적으로 구현하여 간편하게 망 관리를 할 수 있는 Lan 모니터링 시스템을 제시한다.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1521-1529
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• 2009

There is a serious unfairness problem between upstream and downstream flows of AP in IEEE 802.11 Wireless LAN. This problem is because Wireless LAN's DCF MAC protocol provides AP with equal channel access priority to mobile noded. Also, it makes this problem worse that the TCP's Data segment loss is more effective on throughput than the TCP's ACK segment. In this paper, we first make several simulations to analysis the unfairness in the various point of view and to find reasons of the unfairness. Also, this paper presents AP's scheduling scheme to alleviate the unfairness problem and evaluate the scheme through ns2 simulator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.8
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• pp.796-804
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• 1992

This paper presents a design of a backbone network which uses a rigister-Insertion ring structure, The introduction of a high speed register in sertton backbone ring enables high performance inter-network 4ommunicatlons In a simple and modular structure at low cost and Its concurrent communications.. Two or more bridge nodes can be used to construct a register Insertion backbone ring network. The high bandwidth of the backbone ring sup ports heavy traffic for Inter-segment Eornrnunicatlons. The bridge node does both local address filtering to block data entering the ring and remote address filtering to block data entering the local LAN segment . Title local address greatly reduces the rate on the backbone ring and the remote address filterlng greatly reduces the traffic rate on each LAN segment. An feature makes the network the network reconflguratlon simpler and transparent to users. A throughput analysis Is used to deterrune the bandwidth of the backbone rlr)g transmission medium.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.533-535
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• 1998

가상 다중 세그먼트 (Virtual Multi-Segment)란 하나의 LAN이 라우터나 방화벽을 사용하지 않고 가상적으로 여러 개의 세그먼트로 나뉘어진 것을 의미한다. 일반적으로 같은 LAN에 속한 호스트들일지라도 다양한 보안 정책을 가지게 되는데 그 결과로 우회 경로 공격(bypass path attack)이 가능해지고 (Hierarchical)방화벽 시스템을 구성하여 다른 보안 정책을 가진 세스먼트마다 방화벽을 구축하고 있는데 이 방식은 방화벽 시스템을 구성하여 다른 보안 정책을 가진 세그먼트마다 방화벽을 구축하고 있는데 이 방식은 방화벽을 여러 개 설치해야 하는 문제가 있다. 이런 문제를 해결하기 위해 본 논문에서 방화벽을 통해 지나오는 각 연결에 대해서 회선체인을 구성하는 기법을 이용하여 가상적인 다중 세그먼크를 구성한다. 회선체인구성을 효과적으로 수행하기 위해 Thumbpint기법을 사용하는데 이 기법은 동일한 시간대에 모든 회선이 갖는 내용에 대한 요약을 만들어 그 요약들을 가지고 어떤 회선들이 같은 내용을 가지고 있는지를 판단하여 회선체인을 구성하는 기법이다. 본 논문에서 가상 다중 세그먼트 방화벽을 설계와 구현하였다.

• Convergence Security Journal
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• v.6 no.3
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• pp.49-58
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• 2006

Currently there are many standards of network management. They are : SNMP (Simple Network Management Protocol-for Internet management), CMIP (Common Management Information Protocol-standardized by ITU-T and ISO), RMON (Remote network MONitoring-for distributed management of the LAN segment), and so on. Especially RMON has created the many concerns in order to manage subnetworks of a large network, but it has negative aspects. For instance, routers or hubs with RMON capability are expensive to a network manager because of adding heavy management cost. Moreover it imposes a heavier burden on network manager, because it must use a network management tool which will be additionally needed with RMON device. This paper proposes a model of PC based RMON Agent system. The RMON Agent system monitors the traffic on LAN segment through the use of a Virtual Device Driver (VxD), based on PC. In term of cost this model will replace the expensive RMON device, and eventually enable a network manager to manage LAN segment more efficiently, due to reduced cost.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1371-1374
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• 2004

본 논문에서는 내부 LAN(Local area network)에서 MSS(Maximum segment size)의 변화가 네트워크 성능에 미치는 영향에 대하여 분석한다. 내부 LAN에 웹 클라이언트와 웹 서버를 두고 이더넷(Ethernet)이 허용하는 사이즈 내에서 MSS 값의 변화가 네트워크의 성능에 미치는 영향을 분석한다. 처리량(Throughput), 이용률(Utilization), 분실율, 수신율, RTT(Round Trip Time)를 사용하여 성능을 평가하였다. 실험은 네트워크 시뮬레이터 중의 사실상 표준 도구인 NS-2로 한다.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.567-574
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• 2006

VG-AnyLAN is a local area network standard developed by the IEEE 802.12 project. While preserving the frame format of IEEE 802.3, VG-AnyLAN adopts a new medium access control called Demand Priority where transmission requests of stations are arbitrated by a control hub in a round-robin manner. Unlike CSMA/CD which is the medium access control of IEEE 802.3, the Demand Priority, while providing the maximum bound on the packet delay, does not put the limit on the network segment size. In this paper, we analyze the delay and the channel utilization performances of the medium access control of IEEE 802.12 VG-AnyLAN. We develope an analytic model of the system under assumptions that each station generates traffic of the equal priority and that the packets are of fixed length. Using the analytic model, we obtain the recursive expression of the average channel utilization and the average access delay The numerical results obtained via analysis are compared to the simulation results of the system for a partial validation of our analysis.

• Journal of Digital Convergence
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• v.1 no.1
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• pp.235-253
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• 2003

In this research, we have developed a model that can explain the potential customer's needs for the potable Internet service, a concept with 'QoS guaranteed lower-price high speed mobile Internet service. Based on the developed model, we have also derived some empirical implications for the business firms interest in the potable Internet market. The developed model is incorporating a survey result, answering of potential customer's attitude for the portable Internet service, from the subscribers to the Internet service, wireless LAN service, and mobile Internet service. As a result, we have found that a very innovative group, such as wireless LAN users and 20's age group using mobile Internet service, could be the most attractive market segment. Moreover, the aspects of the service coverage and the price competitiveness at the service launching stage could be the most critical success factors for the portable Internet service.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.53-56
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• 2003

Ethernet is one of the most successful LAN technologies. Now gigabit ethernet is available in real network and some network interface cards(NIC) supports TCP segment offloading (TSO), IP checksum offloading(ICO), Jumbo frame and interrupt moderation. If we use this features appropriately, we obtain high throughput with low CPU utilization. This paper represents the network performance by varying above features.