We describe a new scalable application-layer multicast protocol, specifically designed for low-bandwidth, data streaming applications with large receiver sets. Our scheme is based upon a hierarchical clustering of the application-layer multicast peers and can support a number of different data delivery trees with specific desirable properties. We show that group members maintain state for a constant number of other membersand the control overhead is also a constant.

(PRM): a multicast data recovery scheme that improves data delivery ratios while maintaining low end-to-end latencies. PRM has both a proactive and a reactive components; in this paper we describe how PRM can be used to improve the performance of application-layer multicast protocols especially when there are high packet losses and host failures. Through detailed analysis in this paper, we show that this loss recovery technique has efficient scaling properties—the overheads at each overlay node asymptotically decrease to zero with increasing group sizes. As a detailed case study, we show how PRM can be applied to the NICE application-layer multicast protocol. We present detailed simulations of the PRM-enhanced NICE protocol for 10 000 node Internet-like topologies. Simulations show that PRM achieves a high delivery ratio ( 97%) with a low latency bound (600 ms) for environments with high end-to-end network losses (1%–5%) and high topology change rates (5 changes per second) while incurring very low overheads ( 5%). Index Terms—Multicast, networks, overlays, probabilistic forwarding, protocols, resilience. I.

Abstract—Recently, many overlay applications have emerged in the Internet, such as peer-to-peer file sharing, end host multicasting, and content distribution network. Currently, each of these applications requires their proprietary functionality support, such as network topology discovery, routing path selection, fault detection and tolerance, etc. A general unified framework may be a desirable alternative to application-specific overlays. In this paper, we introduce the concept of overlay brokers (OBs). We assume that each autonomous system in the Internet has one or more OBs. These OBs cooperate with each other to form an overlay service network (OSN) and provide overlay service support for overlay applications, such as resource allocation and negotiation, overlay routing, topology discovery, and other functionalities. The scope of our effort is the support of quality-of-service (QoS) in overlay networks. In this paper, our primary focus is on the design of QoSaware routing protocols for overlay networks (QRONs). The goal of QRON is to find a QoS-satisfied overlay path, while trying to balance the overlay traffic among the OBs and the overlay links in the OSN. A subset of OBs, connected by the overlay paths, can form an application specific overlay network for an overlay application. The proposed QRON algorithm adopts a hierarchical methodology that enhances its scalability. Two different types of path selection algorithms are analyzed in our paper. We have simulated the protocols based on the transit-stub topologies produced by GT-ITM. Simulation results have shown that the proposed algorithms perform well in providing QoS-aware overlay routing service. Index Terms—Modified shortest distance path (MSDP), overlay brokers (OBs), overlay routing, overlay service network (OSN), proportional bandwidth shortest path (PBSP), quality-of-service (QoS)-aware routing in overlay networks (QRONs), QoS satisfaction ratio. I.

In this paper, we argue that a broad range of large-scale network services would benefit from a scalable mechanism for delivering state about a random subset of global participants. Key to this approach is ensuring that membership in the subset changes periodically and with uniform representation over all participants. Random subsets could help overcome inherent scaling limitations to services that maintain global state and perform global network probing. It could further improve the routing performance of peer-to-peer distributed hash tables by locating topologically-close nodes. This paper presents the design, implementation, and evaluation of RanSub, a scalable protocol for delivering such state.

In this paper we evaluate a method of using interleaved spanning trees to compose a resilient, high performance overlay mesh. Though spanning trees of arbitrary type could be used to construct an overlay mesh, we focus on a distributed algorithm that computes k minimum spanning trees on an arbitrary graph. The principal motivation behind this strategy is to provide applications with a k-redundant, high quality mesh suitable for demanding applications like A/V broadcast, video conferencing, data collection, multi-path routing, and file mirroring/transfer. We elaborate details of k-MST, pointing out advantages and potential problem points of the protocol, and then analyze its performance using a variety of metrics with simulation as well as a functional PlanetLab implementation.

As the Internet is expected to better support multimedia applications, new services need to be deployed. One of them is the group communication service for one-tomany or many-to-many data delivery. After more than a decade of important research and development efforts, the deployment of multicast routing in the Internet is far behind expectations. Therefore, a first motivation for an alternative group communication service is to bypass the lack of native IP multicast routing. Although less efficient and scalable than native multicast routing, such alternative services are suitable for the purpose. A second possible motivation is to go beyond the limitations of classic multicast routing for very specific working environments. In this article we identify, classify, and discuss some of these alternative approaches. Agroup communication service refers to the ability to send information to several receivers at the same time, using either a one-to-many or many-tomany model. The any-source and source-specific

A moderate amount of recent work has been dedicated to using overlay network to support value-added network service, such as overlay multicast, OverQoS, etc. As it does not require the underlying network support, a lot of new services can be easily deployed across Internet using overlay technique . Overlay service network is a generic service framework which is designed to provide a variety of services to overlay service customers.

Due to the sparse deployment of IP multicast in the Internet today, some researchers have proposed application layer multicast as a new approach to implement widearea multicast services. In this approach multicast functionality is implemented at the end-hosts instead of network routers. Unlike network-layer multicast, application layer multicast requires no infrastructure support and can be easily deployed in the Internet. In this paper, we describe a set of application layer multicast protocols that have been proposed in recent literature, classify them based on some properties and present a comparison of performance and applicability of these schemes.

The rapid growth of time-critical information services and business-oriented applications is making quality of service (QoS) support increasingly important in content distribution. This paper investigates the problem of placing object replicas (e.g., web pages and images) to meet the QoS requirements of clients with the objective of minimizing the replication cost. We consider two classes of service models: replica-aware service and replica-blind service. In the replica-aware model, the servers are aware of the locations of replicas and can therefore direct requests to the nearest replica. We show that the QoS-aware placement problem for replica-aware services is NP-complete. Several heuristic algorithms for efficient computation of suboptimal solutions are proposed and experimentally evaluated. In the replica-blind model, the servers are not aware of the locations of replicas or even their existence. As a result, each replica only serves the requests flowing through it under some given routing strategy. We show that there exist polynomial optimal solutions to the QoS-aware placement problem for replicablind services. Efficient algorithms are proposed to compute the optimal locations of replicas under different cost models.

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 efficient approach to form an overlay mesh for control and maintenance. The mesh can effectively facilitate the overlay multicasting. HostCast improves the reliability of overlay multicast tree and decreases the convergence time as demonstrated by the results obtained via simulation.