• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1256-1265
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• 2003

Content Delivery Network(CDN) is a mechanism to deliver multimedia content to end users on behalf of web content providers. Provider's content is distributed from content server to a set of delivery platforms located at Internet Service Providers(ISPs) through the CDN in order to realize better performance and availability than the system of centralized provider's servers. Existing work on CDN has primarily focused on techniques for efficiently multicasting the content from content server to the delivery platforms or to end users. Multimedia contents usually require broader bandwidth and accordingly WDM broadcast network has been highly recommended for the infrastructure network of CDN. In this paper, we propose methods for partitioning a multicast group into smaller subgroups using the previous status of receivers. Through the computer simulation, we show that proposed algorithm are useful to reduce the average receiver's waiting time and the number of transmissions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12B
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• pp.818-830
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• 2005

Recently, Peer-to-Peer (P2P) overlay networks like CAN, Chord, Pastry and Tapestry offer a novel platform for scalable and decentralized distributed applications. These systems provide efficient and fault-tolerant routing, object location, and load balancing within a self-organizing overlay network. Content Delivery Network (CDN) is an intermediate layer of infrastructure that helps to efficiently deliver the multimedia content from content providers to clients. In this paper, We propose a topology-aware P2P overlay network for CDN, Rosary, in which CDN servers perform Intra-Pastry and Inter-Pastry routing based on a two-level structured overlay network. This proposed system extends pastry by adapting itself to CDN environments, where a semi-hashing based scheme for Intra-Pastry routing is introduced, and dynamic landmark technology is used to construct the topology-aware overlay network. Through simulations on NS-2, it is shown that Rosary is scalable, efficient, and flexible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.178-188
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• 2016

The traffic in the wired and wireless networks has increased exponentially because of increase of smart phone and improvement of PC performance. Multimedia services and file transmission such as Facebook, Youtube occupy a large part of the traffic. CDN is a technique that duplicates the contents on a remote web server of content provider to local CDN servers near clients and chooses the optimal CDN server for providing the content to the client in the event of a content request. In this paper, the content request message between CDN servers and the client used the SCRP algorithm utilizing the MST algorithm and the traffic throughput was optimized. The average response time for the content request is reduced by employing HC_LRU cache algorithm that improves the cache hit ratio. The proposed SCRP and HC_LRU algorithm may build a scalable content delivery network system that efficiently utilizes network resources, achieves traffic localization and prevents bottlenecks.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.10
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• pp.766-770
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• 2009

Recently, users of multimedia files demand a high capacity file via internet. However, it is difficult to guarantee QoS for high capacity files on internet because of its inconstant bandwidth. For guaranteeing the QoS, CDN (Content Delivery Network) is generally used for contents delivery service. Based on CDN, we propose Content Distribution and Management using Metadata (CDM) system which provides advanced transmission method and searching method. To enhance the transmission rate, CDM system supports segment-unit-based transmission method that enables parallel transmission. Also, we propose a distribution method through content based search.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.21-28
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• 2005

최근의 제 2 세대 P2P 시스템은 확장성 있고 장애에 강한 분산 해쉬 테이블을 이용하여 대규모 P2P 애플리케이션을 위한 셀프-오거나이징 (Selforganizing)기술을 제공한다. 하지만 기존의 Pastry의 경우 해쉬 기반 기법을 적용하였기 때문에 사용자들의 요청이 빈번한 콘텐츠의 경우 한 노드로 네트워크의 전송 부하가 집중되는 현상이 발생할 수 있어 CDN 시스템에 적합하지 않았다. 본 논문에서는 이러한 문제점을 해결하기 위하여 CDN(Content Delivery Network) 환경에 적합하게 확장한 Rosary 오버레이 네트워크를 제안한다. 본 논문에서 제안하는 Rosary는 Pastry를 Inter-Pastry와 Intra-Pastry로 나누어 CDN 환경에 맞게 확장하였고 애플리케이션-레벨 멀티캐스팅(Applicatio-Level Multicasting)을 가능하도록 했으며 세미 해쉬 스킴(Semi Hash Scheme)을 적용함으로서 CDN 환경에 맞게 수정 하고 확장하였다.

• ETRI Journal
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• v.36 no.5
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• pp.819-828
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• 2014

To solve the increasing popularity of video streaming services over the Internet, recent research activities have addressed the locality of content delivery from a network edge by introducing a storage module into a router. To employ in-network caching and persistent request routing, this paper introduces a hybrid content delivery network (CDN) system combining novel content routers in an underlay together with a traditional CDN server in an overlay. This system first selects the most suitable delivery scheme (that is, multicast or broadcast) for the content in question and then allocates an appropriate number of channels based on a consideration of the content's popularity. The proposed scheme aims to minimize traffic volume and achieve optimal delivery cost, since the most popular content is delivered through broadcast channels and the least popular through multicast channels. The performance of the adaptive scheme is clearly evaluated and compared against both the multicast and broadcast schemes in terms of the optimal in-network caching size and number of unicast channels in a content router to observe the significant impact of our proposed scheme.

• Journal of the Korea Society of Computer and Information
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• v.23 no.9
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• pp.35-42
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• 2018

In this paper, we propose an optimal streaming service method based on Hybrid CDN/P2P architecture. Recently, video streaming utilizes a CDN (Content Delivery Network) operation technique based on a Proxy Server, which is an end node located close to a user. However, since CDN has a fixed network traffic bandwidth and data information exchange among CDNs in the network is not smooth, it is difficult to guarantee traffic congestion and quality of image service. In the hybrid CDN/P2P network, a data selection technique is used to select only the data that is expected to be continuously requested among all the data in order to guarantee the QoS of the user who utilizes the limited bandwidth efficiently. In order to search user requested data, this technique effectively retrieves the storage information of the constituent nodes of CDN and P2P, and stores the new image information and calculates the deletion priority based on the request possibility as needed. Therefore, the streaming service scheme proposed in this paper can effectively improve the quality of the video streaming service on the network.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.725-733
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• 2008

CDN(Content Delivery Network) has been used as contents transmission network for transmitting high capacity contents fastly and stably. Main goals of CDN are efficient distribution and management high capacity contents. Current CDN distributes contents by managing contents based on basic metadata created by contents provider. However, existing CDN management system doesn't provide a method for applying additional metadata in content itself that is necessary for efficient contents management and distribution. Since the existing system can not annotate additional information in metadata about contents itself, and can not search contents that user wants. This paper proposes a method for applying additional metadata in existing CDN and implemented it as contents metadata management system(CMMS). A user can search needed contents effectively via CMMS. Also, the searched result can help selecting and managing contents to distribute in CDN.

• Journal of the Korea Society of Computer and Information
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• v.9 no.3
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• pp.149-155
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• 2004

This paper describes the self-adaptive Content Service Network (CSN) on Application Level Active Network (ALAN). Web caching technology comprises Content Delivery Network (CDN) for content distribution as well as Content Service Network (CSN) for service distribution. The IETF working group on Open Pluggalble Edge Service (OPES) is the works closely related to CSN. But it can be expected that the self-adaptation in ubiquitous computing environment will be deployed. The existing content service on CSN lacks in considering self-adaptation. This results in inability of existing network to support the additional services. Therefore, in order to address the limitations of the existing networks, this paper suggests Self-adaptive Content Service Network (CSN) using the GME and the extended ALAN to insert intelligence into the existing network.