• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5B
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• pp.378-389
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• 2006

An IP address lookup scheme has become a critical issue increasingly for high-speed networking techniques due to the advent of IPv6 based on 128bit. In this paper, a novel global IPv6 unicast address lookup scheme is proposed for next generation internet routers. The proposed scheme perform a variable multiple hashing based on prefix grouping. Accordingly, it should not only minimize overflows with the proper number of memory modules, but also reduce a memory size required to organize forwarding tables. It has the fast building and searching mechanisms for forwarding tables during only a single memory access. Besides, it is easy to update forwarding tables incrementally. In the simulation using CERNET routing data as a 6bone test phase, we compared the proposed scheme with a similar scheme using a uniform multiple hashing. As a result, we verified that the number of overflows is reduced by 50% and the size of memory for forwarding tables is shrunken by 15% with 8 tables.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1297-1300
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• 2002

포워딩 엔진은 외부 인터페이스를 통해서 들어오는 패킷에 대해서 IP 주소를 기반으로 목적지로 향하는 다음 홉을 결정한다. 이러한 고속의 패킷 처리를 위한 포워딩 엔진을 설계함에 있어서 IP 주소 탐색은 중요한 요인이다. 본 논문에서는 검색경로 압축 트라이에 기반한 IP 주소 탐색 알고리즘을 병렬화 하는 기법을 제시한다. 제시된 병렬화를 통해서 IP 주소 탐색의 메모리 접근 횟수글 줄일 수 있으며, 고성능의 패킷 포워딩 엔진에 적용할 수 있다.

• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.659-672
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• 2004

A Mobile Ad hoc Network (MANET) is a group of independent mobile computing nodes that consist of a multi-hop wireless network without a central administration or any infrastructure. Every node that wants to join a MANET must obtain an address for communication. Having a centralized DHCP server that provides addresses to nodes, we can easily and automatically obtain addresses. However, a MANET lacks any fixed infrastructure such as a DHCP server. We therefore propose a distributed address autoconfiguration approach for a MANET using a reserved address and optimistic Duplicated Address Detection (DAD). The reserved address helps to reduce the allocation latency, and the optimistic DAD guarantees the uniqueness of addresses and lessens communication overhead. We then suggest methods of handling network partition and network merging situations, and go on to evaluate our approach through simulations. The simulation result shows that our scheme guarantees the uniqueness of allocated address and considerably improves allocation latency and communication overheads.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.11
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• pp.613-619
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• 2001

The IP address lookup problem is to find the longest matching IP prefix for a given IP address from the routing table and has been a central bottleneck in speeding up the Internet. In this paper, we propose a new algorithm for this problem based on the segment tree data structure. Given n IP prefixes, our algorithm can do IP address in Ο(log n) time. It also handles the insertion and deletion of IP prefixes efficiently without rebuilding the total data structure.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.58-61
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• 2006

대량으로 존재하는 웹자원에 대한 디렉토리 및 검색서비스를 제공하는 포털서비스로의 집중화 현상이 계속해서 심화되고 있다. 상대적으로 주소를 통한 자원으로의 접근은 약화되고 있다. 포털서비스와 접근수단 그리고 최종 목적지인 콘텐츠사이트 간의 확률적 모델을 통하여 포털사이트로의 집중화 현상이 콘텐츠 접근 모델에 있어서의 구조적인 특징에 기인함을 알 수 있었다. 많은 이용자들이 시작페이지로 포털사이트를 설정하고 있고, 주소를 입력 할 때는 주소창 보다는 포털의 검색창에 입력하고 있음으로 해서 포털서비스가 주소서비스를 대체하고 있다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.21-28
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• 2008

In this paper, we proposed an algorithm that reduces call setup time between the IP PBXs installed in the main office and several branch offices. In the IP PBXs installed in branch offices, we prepare some internal memory spaces, and they keep the frequently used extension numbers and the corresponding IP PBX's addresses. In order to call an extension number registered to the other remote IP PBX from an extension number registered to the local IP PBX, the local PBX searches for the destined extension from its internal memory first. If the extension is found, then the local PBX uses its corresponding IP PBX address stored along with the extension, instead of making a query to the main office's IP PBX. By this technique, we could shorten the average call setup time and verified it by an experiment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.339-348
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• 2004

Packet classification is an important factor to support various services such as QoS guarantee and VPN for users in Internet. Packet classification is a searching process for best matching rule on rule tables by employing multi-field such as source address, protocol, and port number as well as destination address in If header. In this paper, we propose hardware based packet classification algorithm by employing tree bitmap of multi-bit trio. We divided prefixes of searching fields and rule into multi-bit stride, and perform a rule searching with multi-bit of fixed size. The proposed scheme can reduce the access times taking for rule search by employing indexing key in a fixed size of upper bits of rule prefixes. We also employ a marker prefixes in order to remove backtracking during searching a rule. In this paper, we generate two dimensional random rule set of source address and destination address using routing tables provided by IPMA Project, and compare its memory usages and performance.

• Smart Media Journal
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• v.8 no.2
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• pp.86-93
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• 2019

The purpose of this study is to develop walk score application GUI in a smart device for improving user convenience. This study uses the walk score dataset of Seoul City developed in previous studies. Application GUI consists of five parts: address input window and search button, detail information (address, latitude, longitude, walk score), window switching and input window for a number of data, data input window, and menu button. For verifying application GUI, this study uses 12 locations (sets of address, latitude, longitude, and walk score) near Gangnam Station and Myungdong Station in Seoul in several scenarios. First, this study checks if the application has been implemented with address and keyword search options. Then, new data insertion and file output operations are evaluated. The application system developed in this study operated properly in all scenarios. This walk score application can be a useful device in our daily lives.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1095-1098
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• 2004

IP VPN의 사용은 현재 보편화 되었고 네트워크 장비의 통합 추세에 따라 IP VPN과 방화벽 통합제품의 생산이 활발히 이루어지고 있다. 통합 보안 제품은 비용 효율성과 관리의 편리성, 확장성, 유연성과 같은 장점을 제공하지만 높은 성능 지원을 요구한다. 방화벽의 성능 인자의 하나로서 정책의 개수는 그 수에 비례하여 검색 시간이 지연되는 문제를 발생시키고, 이러한 성능 저하 문제는 VPN과 통합 시 더욱 가중된다. 더욱이 차세대 네트워크인 IPv6로 환경에서는 IP의 비트수가 증가하여 검색 성능 문제 해결이 필수적으로 요구된다. 본 논문에서는 이러한 통합 제품의 검색 성능 문제에 관한 해결 방안으로 IPv6 주소의 특성을 사용한 메커니즘을 제안한다. 제시한 메커니즘은 보안 정책 테이블의 주소 필드를 IPv6 주소에 포함된 인터페이스 식별자로 대체하여 보안 정책 테이블의 검색 속도를 향상시키는 방법이다. 이 방법은 차세대 네트워크 환경에서 주목 되고 있는 보안 및 성능 문제에 대해 큰 역할을 할 것으로 기대된다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.9
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• pp.38-45
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• 2007

With the emergence of new applications, packet classification is essential for supporting advanced internet applications, such as network security and QoS provisioning. As the packet classification on multiple-fields is a difficult and time consuming problem, internet routers need to classify incoming packet quickly into flows. In this paper, we present multi-phase packet classification architecture using an internal buffer for fast packet processing. Using internal buffer between address pair searching phase and remained fields searching phases, we can hide latency from the characteristic that search times of source and destination header fields are different. Moreover we guarantee the improvement by using single entry caching. The proposed architecture is easy to apply to different needs owing to its simplicity and generality.