Group communication has become increasingly important in mobile ad hoc networks (MANET). Current multicast routing protocols in MANET have been shown to have large overhead due to dynamic network topology. To overcome this problem, there is a recent shift towards stateless multicast in small groups (DDM [1]). DDM queries the underlying unicast routing protocol to forward data packets towards members of a multicast group. The multicast distribution tree in DDM is implicit and cannot be controlled by the upper transport and application layers.

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In this paper, we present a new online algorithm for dynamically routing bandwidth guaranteed label switched paths (LSPs). LSP set-up requests are represented in terms of a pair of ingress and egress routers as well as its bandwidth requirement, and arrive one by one. There is no aprioriknowledge regarding future LSP set-uprequests and their characteristics. Our proposed algorithm considers not only the importance of critical links, but also the degree of their importance to routing possible future LSP set-uprequests by characterizing their normalized bandwidth contribution to routing future LSP demands. Moreover, link residual bandwidth information, i.e., the link’s capability of routing future LSPs, is also incorporated. Simulation results show that our proposed algorithm performs better than the best known bandwidth guaranteed routing algorithm, the minimum interference routing algorithm, in terms of LSP rejection rate under both static and dynamic LSP set-uprequest arrivals.

In the age of multimedia and high-sl)eed networks', multicast is one of the mechanisms by which the power of the Internet can be further harnessed in an efficient manner. When more than one receiver is interested in receiving a transmission from a single or a set of senders, multicast is the most efficient and viable mechanism. In the protocol stack of the network, multicast is best implemented in the network layer in the form of a multicast routing protocol to select the best path for the transmission. The other layers' of the protocol stack provide additional features for multicast.

Group communication has become increasingly important in mobile ad hoc networks (MANET). Current multicast routing protocols in MANET have been shown to incur large overhead due to dynamic network topology. To overcome this problem, there is a trend towards stateless multicast. For example, DDM [1] queries the underlying unicast routing protocol to forward data packets towards members of a multicast group without keeping the multicast session state information. In this paper

Various real-time services, like webcasting, audio/videoconferencing and telemedicine, are being deployed over the Internet. This requires the network to provide the guarantee of the service being provided to the receiver. The needs of the application is specified in terms of the Quality of Service (QoS) metrics like desired bandwidth, response time, etc. End-to-end QoS can be provided most efficiently when each layer of the protocol stack translates the application provided requirement into layer specific requirement and satisfies the same. Network layer has a critical role to play in the QoS provision process. It provides the desired QoS by considering the QoS metrics in the path selection process. The focus of this paper is on the QoS routing algorithms and protocols for unicast and multicast in the IPv4 based Internet that constrains or optimizes an individual or combination of metrics. The desired features of a router supporting QoS have been discussed in detail. QoS routing leads to an increase

This document gives an overview of most of the directions taken by research in the multicast area. We first introduce the basic concepts. The following sections deal with high level services that can (or must) be provided on top of the underlying multicast routing infrastructure. Then we consider new evolutions in multicast routing: new protocols, their large scale deployment, and future trends. Finally we discuss multicast tools and applications.

Mobile Ad-hoc networking has been considered as one of the most important and essential technologies that support future Pervasive Computing Scenarios and 4G networks. In a mobile Ad-hoc Network (MANET), support for multicast communication is essential in order to minimize overhead for group communication. For group conferencing services, controlling the end-to-end delay is important to provide high quality communication. In this paper, we present QAMNet, an approach to improve the Quality of Service (QoS) for multicast communication in MANETs. We extend existing approaches of mesh based multicasting by introducing traffic prioritization, distributed resource probing and admission control mechanisms, adaptive rate control of non-real-time traffic based on Medium Access Control (MAC) layer feedback so as to maintain low delay and required throughput for real-time multicast flows. Simulation results show that our approach is as scalable as mesh based deliver structures and does not require significantly more states than normal mesh based multicasting protocols. As we reuse signaling packets of mesh based multicast packets, we do not introduce additional signaling overhead.

The proliferation of QoS-aware group applications coupled with the limited availability of network resources demands for efficient mechanisms to support QoS multicasting. During a life-cycle of a multicast session, three important events can occur: membership dynamics, network dynamics, and traffic dynamics. The first two are concerned with maintaining a good quality (cost) multicast tree taking into account dynamic join/leave of members, and changes in network topology due to link/node failures/additions, respectively. The third aspect is concerned with flow, congestion, and error control. There has been many solutions proposed for dealing with each of these issues. However, the issue of tree migration has not been addressed as part of these solutions. In this paper, we highlight the importance of tree migration as a mechanism for handling membership and network dynamics in core-based 1 multicasting, prove that it is NP-Complete, and propose four heuristic algorithms for it. The proposed algorithms are evaluated under two performance metrics: service disruption and resource wastage. Our simulation studies show that two of the algorithms offer comparable performance to that of the other two, in addition to being highly scalable and easily implementable.

We suggest a formal model to represent and solve the multicast routing problem in multicast networks. To attain this, we model the network adapting it to a weighted and-or graph, where the weight on a connector corresponds to the cost of sending a packet on the network link modelled by that connector. Then, we use the Soft Constraint Logic Programming (SCLP) framework as a convenient declarative programming environment in which to specify related problems. In particular, we show how the semantics of an SCLP program computes the best tree in the corresponding and-or graph: this result can be adopted to find, from a given source node, the multicast distribution tree having minimum cost and reaching all the destination nodes of the multicast communication. The costs on the connectors can be described also as vectors (multidimensional costs), each component representing a different Quality of Service metric value. Therefore, the construction of the best tree may involve a set of criteria, all of which are to be optimized (multi-criteria problem), e.g. maximum global bandwidth and minimum delay that can be experienced on a single link.