• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.463-465
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• 1999

인터넷으로 연결된 모든 장치는 각 나라마다 정해진 권위기관으로부터 고유한 IP 주소를 할당 받게 되는데, 현재 Internet Network Center(Inter NIC)라는 조직에서 이를 전체적으로 관장하고 있다. 최근 인터넷 사용이 급속히 확산되면서 인터넷을 이용하는 모든 장치에 고유 IP 주소를 할당하게 될 경우 고유 주소 체계의 사용 가능한 IP 주소 고갈이라는 문제에 직면하게 되었다. 그러나 이러한 문제는 내부 근거리 통신망(LAN)과 인터넷 상에 IP 주소를 변환시켜 주는 역할을 하는 네트워크 주소 변환(NAT: Network Address Translation) 기능을 이용하여 보완할 수 있다. 본 연구에서는 사설망 사용자의 인터넷 접속을 제공하는 것으로 기존 라우터에 NAT 기능을 적용하여 라우터가 보유한 공인 주소를 각 사용자가 공유하여 인터넷 접속을 제공하는 것으로 기존 라우터에 NAT 기능을 적용하여 라우터가 보유한 공인 주소를 각 사용자가 공유하여 인터넷 접속을 시도하는 것으로 사설망의 IP주소를 공인된 인터넷 주소로 변환시켜 외부로 전송하므로써 가능하다. 또한, 주소 변환 과정으로 사설망에서 사용하는 IP주소가 NAT 기능으로 IP주소가 변경되어 외부 침입자가 사설망의 존재를 알 수 없어 침입을 막는 간접적인 방화벽 기능도 수행한다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.2
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• pp.77-88
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• 2009

According to the size of NAND flash memory as the storage system of mobile device becomes large, the performance of address translation and life cycle management in FTL (Flash Translation Layer) to interact with file system becomes very important. In this paper, we propose the continuity counters, which represent the number of continuous physical blocks whose logical addresses are consecutive, to reduce the number of address translation. Furthermore we propose the prefetching method which preloads frequently accessed pages into main memory to enhance I/O performance of flash memory. Besides, we use the 2-bit write prediction and asynchronous writing method to predict addresses repeatedly referenced from host and prevent from writing overhead. The experiments show that the proposed method improves the I/O performance and extends the life cycle of flash memory. As a result, proposed CFTL (Clustered Flash Translation Layer)'s performance of address translation is faster 20% than conventional FTLs. Furthermore, CFTL is reduced about 50% writing time than that of conventional FTLs.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.652-655
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• 2002

The next generation Internet Protocol IPv6 that is appeared to solve the exhausting problem is now widely deployed in a testbed or commercial site. To successfully deploy IPv6, interoperation with exist IPv4 hosts and routers and interactions with many IPv4 applications are more important. The NAT-PT (Network Address Translation-Protocol Translation) among IPv6 transition mechanism enables the communication between IPv4 and IPv6 host with translating IPv4 address and IPv6 address. But for DNS and FTP, another specific mechanism is needed when internet address is included in packet payload area. This paper describes the design and implementation of IPv6-support FTP-ALG, (Application Layer Gateway) to enable FTP service between IPv4 node and IPv6 node.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.9-15
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• 2017

This paper presents an efficient FTL for NAND flash based SSDs. Address translation information of page mapping based FTLs is stored on flash memory pages and address translation cache keeps frequently accessed entries. The proposed FTL of this paper reduces response time by considering both of temporal and spacial localities of page access patterns in translation cache management. The localities of several well-known traces are evaluated and determine the structure of the cache for high hit ratio. A simulation with several well-known traces shows that the presented FTL reduces response time in comparison to previous FTLs and can be used with relatively small size of caches.

• Journal of the Korean Geophysical Society
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• v.4 no.4
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• pp.239-249
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• 2001

NAT (Network Address Translation) is an IP address modification protocol that translates private IP addresses into authentic Internet addresses. The main features of NAT are to improve network security and to save IP addresses. Generally speaking, in order to perform its functionality. NAT uses the address informaiton in the packet header. Certain application protocols, however, use the information in the packet data as well as the imformation in the packet header to perform end-to-end communication. Therefor, to support these types of application protocols, NAT should be able to perform appropriate translation of protocol information in the packet data. In this thesis, we design and implement a method which translates virtual IP information in the packet data into real IP information by using port proxy server.

• The KIPS Transactions:PartC
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• v.11C no.5
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• pp.683-688
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• 2004

NAT is a very useful IP address translation technique that allows two connected networks using different and incompatible IP address schemes. But it is impractical to use NAT for an application which uses the encrypted IP packet, embedding IP addresses inside of data payloads, to guarantee End-to-End Security such as IPSec. In addition to rewriting the source/destination IP addresses in the packet, NAT must modify IP checksum every time, which could lead to considerable performance decrease of the overall system in the process of the address translation. RSIP is an alternative to solve these disadvantages of NAT and the address shortage problems. Both NAT and RSIP divide networks into inside and outside addressing realms. NAT translates addresses between internal network and external network, but RSIP uses a borrowed external address for outside communications. RSIP server assigns a routable public address to a RSIP client temporarily to communicate with public net-work outside of the private network. In this paper, RSIP gateway for intranet environment is designed and its performance is evaluated. From the results of performance evaluation, we knew that RSIP is operated less sensitive to the data traffic. Also, the experiment shows that RSIP performs better than NAT when the transmission data grows larger.

• The KIPS Transactions:PartD
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• v.17D no.6
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• pp.383-394
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• 2010

Flash memory based SSDs are currently being considered as a promising candidate for replacing hard disks due to several superior features such as shorter access time, lower power consumption and better shock resistance. However, SSDs have different characteristics from hard disk such as difference of unit and time for read, write and erase operation and impossibility for over-writing. Because of these reasons, SSDs have disadvantages on hard disk based systems, so FTL(Flash Translation Layer) is designed to increase SSDs' efficiency. In this paper, we propose an advanced logical address mapping method for increasing SSDs' performance, which is named HAMM(Hybrid Address Mapping Method). HAMM addresses drawbacks of previous block-mapping method and super-block-mapping method and takes advantages of them. We experimented our method on our own SSDs simulator. In the experiments, we confirmed that HAMM uses storage area more efficiently than super-block-mapping method, given the same buffer size. In addition, HAMM used smaller memory than block-mapping method to construct mapping table, demonstrating almost same performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3B
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• pp.217-223
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• 2003

In spite of widely deploying information broadcasting services based on Internet, there are some limitations to use them due to the bound of Internet protocol. In this paper, a new Internet broadcasting technology for access network is proposed by employing IP address translation function in base station. There are some advantages such as; no need to allocate IP address to receiver, no need to know web site address, and reduction of traffic for server and network. Especially, this technology is very proper to wireless Internet local information broadcasting.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.15-18
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• 2003

Flash memory becomes more important for its fast access speed, low-power, shock resistance and nonvolatile storage. But its native restrictions that have limited 1ifetime, inability of update in place, different size unit of read/write and erase operations need to managed by FTL(Flash Translation Layer). FTL has to control the wear-leveling, address mapping, bad block management of flash memory. In this paper, we focuses on the fast access to address mapping table and proposed the way of faster valid page search in the flash memory using the VPLT(Valid Page Lookup Table). This method is expected to decrease the frequency of access of flash memory that have an significant effect on performance of read and block-transfer operations. For the validations, we implemented the FTL based on Windows CE platform and obtained an improved result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.6
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• pp.526-532
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• 2004

The insufficiency on IP address cause to develope a new internet protocol, IPv6 that the length of address field is expanded. But there are actually many problems on applying and operating this standard for internet. Though NAT(Network Address Translation) is instead of it, NAT has the characteristics that is not allowed to access from outside. This is a big merit in security but a week point because the access from outside should be allowed when a small organization operate web sever or mail server. Therefore, this paper proposes the expanded NAT which can solve such problems as modifying the table of NAT. Furthermore, the function of existing VPN(Virtual Private Network) will be acceptable partly through such a method that provide the linkage among VPNs.