Though the merits of IP-based multicast is undeniable, the deployment of IP multicast has met many difficulties. In the past several years, lots of research work have been done on overlay multicast (end-system multicast, application-layer multicast). In this paper, we propose a new overlay multicast protocol: HostCast. Besides constructing a data delivery tree, HostCast uses a simple and effici...

To enhance the performance of overlay multicast networks, the overlay multicast tree should be optimized. This optimization problem is a minimum diameter, degree-limited spanning tree (MDDLST) problem which is known to be NP-Hard. We present a new scheme to optimize an overlay multicast tree dynamically. Our algorithm can adapt the tree structure to the dynamic membership and network situation....

In the design and implementation of the overlay architecture most peer-to-peer (P2P) systems rely on the underlay network to provide them with basic connectivity. Therefore, the intrinsic features of the underlay network determine the efficiency of the overlay. Accordingly, studying the interdependency of the overlay and underlay networks leads to a better understanding of P2P behaviour. We pre...

Recent years have seen a tremendous growth of interests in streaming continuous media such as video data over the Internet. This would create an enormous increase in the demand on various server and networking resources. To minimize service delays and to reduce loads placed on these resources, we propose an Overlay Caching Scheme (OCS) for overlay networks. OCS utilizes virtual cache structures...

Overlay networks create new networking services using nodes that communicate using pre-existing networks. They are often optimized for specific applications and targeted at niche vertical domains, but lack interoperability with which their functionalities can be shared. MOSAIC is a declarative platform for constructing new overlay networks from multiple existing overlays, each possessing a subs...

In this paper, we conduct extensive simulations to understand the properties of the overlay generated by BitTorrent. We start by analyzing how the overlay properties impact the efficiency of BitTorrent. We focus on the average peer set size (i.e., average number of neighbors), the time for a peer to reach its maximum peer set size, and the diameter of the overlay. In particular, we show that th...

Abs t rac t We define, for an overlay built on top of an ad hoc network, a simple criterion for neighbourhood: two overlay nodes are neighbours if and only if there exists a path between them of at most R hops, and R is called the (overlay) neighbourhood range. A small R may result in a disconnected overlay, while an unnecessarily large R would generate extra control traffic. We are interested ...

We address the problem of optimal routing in overlay networks. An overlay network is constructed by adding new overlay nodes on top of a legacy network. The overlay nodes are capable of implementing any dynamic routing policy, however, the legacy underlay has a fixed, single path routing scheme and uses a simple work-conserving forwarding policy. Moreover, the underlay routes are pre-determined...

我々は,ネットワークオーバレイのアルゴリズム研究基盤として,オーバレイ構築ツールキット Overlay Weaver を開発・配布している.これを用いることで,計算機 1 台上で繰り返し動作試験を 行いながら,少ないコード量で structured オーバレイのアルゴリズムを実装できる.また,アルゴ リズムの差し替え,および,計算機 1台上での数千ノード規模のエミュレーションが可能であるため, アルゴリズム間の公正な比較を行うことができる.同時に,こうして実装したアルゴリズムはそのま ま実ネットワーク上で動作するため,アルゴリズム研究の成果が直接アプリケーションに結び付く. 本ツールキットでは,アルゴリズムの実装を容易なものとするために,各アルゴリズムに共通する ルーティング処理をアルゴリズム実装から分離した.本論文では,この分離を可能とする両者間のイ ンタフェースを提案する.この分...