• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.7
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• pp.1599-1606
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• 1997

The software RAID file system is defined as the system which distributes data redundantly across an aray of disks attached to each workstations connected on a high-speed network. This provides high throughput as well as higher availability. In this paper, we present an efficient caching scheme for the software RAID filte system. The performance of this schmem is compared to two other schemes previously proposed for convnetional file systems and adapted for the software RAID file system. As in hardware RAID systems, small-writes to be the performance bottleneck in softwre RAID filte systems. To tackle this problem, we logically divide the cache into two levels. By keeping old data and parity val7ues in the second-level cache we were able to eliminate much of the extra disk reads and writes necessary for write-back of dirty blocks. Using track driven simulations we show that the proposed scheme improves performance for both the average response time and the average system busy time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.97-99
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• 2021

Edge caching can provide high QoE by reducing traffic in the backhaul network and reducing latency in video streaming services. But due to the limited capacity of edge cache, large amounts of content cannot be cached. In this paper, we propose an edge-fog prefix caching that reduces playback delay by caching prefixes of video content on edges and storing the rest in fog cache.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.155-163
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• 2014

To enhance network efficiency, content-centric networking (CCN) proposes that intermediated network nodes on a content-delivery path temporally cache transmitted contents. Then if an intermediated node receives a content request message (Interest) for previously cached content, the node directly transmits the cached content as a response message (Data) to requestors and finishes the transmission of the received Interest. Since Interest is performed by intermediated network nodes, it is possible to efficiently transmit contents and to effectively solve a network congestion problem caused around contents sources. For that, CCN utilizes both content store to temporarily cache content and pending Interest table (PIT) to record Interest incoming Face. However, it has mentioned the possibility of denial service attack using both the limitation of PIT resource and fake Interests. In this paper, we briefly describe the presented PIT flooding attack utilizing fake Interest. Then we introduce new attack possibility using fake Data and propose a countermeasure for the proposed attack. Also we evaluate the performance of our proposal.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.259-274
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• 2005

In this paper, we propose a methodology to estimate the number of users in e-Commerce systems. There have been a lot of previous work under the closed-LAN system environment. But the study on the number of acceptable users in real network environment is hard to find in the literature. Our research applies a Hybrid Simulation by using QoS results for end-to-end high-speed Internet service, and experiments are performed with regard to LAN and WAN, network equipments, and various network bandwidth. As result of the experiments we observed that the response time of high-speed Internet service media(Wireless LAN, ADSL, Cable, VDSL) depends heavily on the sequence and depth of transactions and on the ratio of transactional and non-transactional interactions. That is, as the network and application get more loads, the number of acceptable users decreases. By adding a cache server and an L4 switch to the simulation model, we analysed the changes in the number of users and client response time.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.407-416
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• 2009

Recently, various application services in wireless sensor networks are more considered than before, and thus reliable and secure communication of sensor network is turning out as one of essential issues. This paper studies such communication in IEEE 802.15.4 based sensor network. We present IMHRS (IEEE 802.15.4 MAC-based Hybrid hop-by-hop Reliability Scheme) employing EHHR (Enhanced Hop-by-Hop Reliability), which uses Hop-cache and Hop-ack and ALC (Adaptive Link Control), which considers link status and packet type. Also, by selecting security suite depending on network and application type, energy efficiency is considered based on HAS (Hybrid Adaptive Security) Framework. The presented schemes are evaluated by simulations and experiments. Besides, the prototype system is developed and tested to show the potential efficiency.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.5
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• pp.817-826
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• 2024

Modern networks and the internet now handle an unprecedented volume of data packets, making efficient traffic management increasingly challenging. To address this issue, next-generation network architectures like Content-Centric Networks (CCN) have emerged. CCN focuses on content-centric data processing to minimize unnecessary traffic. Traditional internet architectures primarily use an end-to-end approach, where multiple users requesting content simultaneously can lead to a surge in traffic. In contrast, CCN optimizes traffic by utilizing in-network cache functions, reducing the time required to serve content to users. Therefore, in CCN, it is crucial to determine which caching policy to apply for effective content management. Existing research has proposed various caching methods based on factors like Hit count and producer popularity. However, these methods often fail to consider content type, resulting in situations where less popular videos are removed in favor of images, potentially increasing network traffic. This study proposes a caching strategy that distinguishes between content type and producer popularity to further reduce network traffic and response time.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.223-226
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• 2003

In this paper, we propose new agent discovery and route discovery schemes to support Mobile IP (MIP) in Ad Hoc networks with wireless backbone. The wireless backbone consisting of stationary wireless routers and Internet gateways (IGs) is a kind of wireless access network of IP-based core network. The proposed scheme utilizes favorable features of wireless backbone such as stable links and no energy constraints. In the agent discovery scheme, backbone-limited periodic Agent Advertisement (AA) and proxy-AA messages are used, which reduce network-wide broadcasting overhead caused by AA and Agent Solicitation messages and decentralize MIP processing overhead in IGs. In order to reduce delay time and control message overhead during route discovery far the destination outside Ad Hoc network, we propose a cache-based scheme which can be easily added to the conventional on-demand routing protocols. The proposed schemes can reduce control overhead during agent discovery and route discovery, and efficiently support MIP in Ad Hoc network with wireless backbone.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.540-543
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• 2004

Address Resolution Protocol (ARP) cache poisoning is a MAC layer attack that can only be carried out when an attacker is connected to the same local network as the target machines. ARP is not a new problem, but wireless network introduces a new attack point and more vulnerable to the attack. The attack on wireless network cannot be detected by current detection tool installed on wired network. In order to detect the ARP poisoning attack, there must be a ARP poisoning detection tool for wireless LAN environment. This paper proposes linux-based ARP poisoning detection system equipped with wireless LAN card and Host AP device driver

• The Journal of Information Technology and Database
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• v.8 no.2
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• pp.41-60
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• 2001

Despite the growth in Internet users, demand for multi-medial, large data files and resulting explosive growth in data traffic, there has been lack of investment in Middle-Mile, interconnection of various networks, resulting in bottleneck effect, which is acerbating. One strategy to overcome such network bottleneck is Content Delivery Network (CDN). CDN does not achieve efficient delivery of large file data through physical improvement/increase in network capacity, but by delivering large file contents, the cause of bottlenecks, from distributed servers. Since it is impracticable to physically improve networks capacity to accommodate the growth in internet traffic, CON, by strong CPs contents at cache servers deployed at major ISPs networks, is able to deliver requested contents to the requesting Web clients without the loss of data and long latency.

• Journal of Communications and Networks
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• v.17 no.2
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• pp.118-125
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• 2015

In this paper, we propose a method to reduce mobile social network services (SNSs) traffic using a mobile integrated SNS gateway (MISG) to improve network communication performance between the mobile client and SNS servers. The gateway connects the client and SNS servers using the contents adapter and the web service adapter and helps to improve communication performance using its cache engine. An integrated SNS application, the user's client, communicates with the gateway server using integrated SNS protocol. In addition, the gateway can alert the client to new SNS contents because of the broker server implemented by the message queuing telemetry transport protocol. We design and develop the modules of the gateway server and the integrated SNS application. We then measure the performance of MISG in terms of content response time and describe the result of the experiment.