Tree-shared multicast in optical burst-switched WDM networks

In this paper, we propose a new multicast scheme called tree-shared multicasting (TS-MCAST) in optical burst-switched wavelength-division-multiplexing networks, taking into consideration overheads due to control packets and guard bands (GBs) associated with data bursts. In TS-MCAST, multicast traffic belonging to multiple multicast sessions from the same source-edge node to possibly different destination-edge nodes can be multiplexed together in a data burst, which is delivered via a shared multicast tree. To support TS-MCAST, we propose three tree-sharing strategies based on equal coverage, super coverage, and overlapping coverage, and present a simple shared multicast tree-construction algorithm. For performance comparison, we consider two other multicast schemes: separate multicasting (S-MCAST) and multiple unicasting (M-UCAST). We show that TS-MCAST outperforms S-MCAST and M-UCAST in terms of bandwidth consumed and processing load (i.e., number of control packets) incurred for a given amount of multicast traffic under the same unicast traffic load with static multicast sessions and membership.     

Challenges and advances in using IP multicast for overlay data delivery - [consumer communications and networking]

IP multicast and overlay multicast have been proposed for one-to-many data delivery over the Internet. Compared to overlay multicast, IP multicast is less deployed but can achieve higher delivery efficiency. Researchers hence study how to combine IP multicast with overlay multicast in order to achieve both high deployability and high delivery efficiency. This combination is called island multicast. In this article we present a comprehensive survey of recent research on island multicast. We investigate the general architecture and key components of island multicast. We then discuss the core issue in island multicast: how to set up delivery connections across multiple multicast domains. We finally discuss open issues for future research.     

A multicast mechanism for UMTS

This article aims to investigate multicast deployment issues and requirements in the context of UMTS networks. We propose a multicast mechanism that supports resource-efficient multicast packet delivery. The proposed scheme allows multicast packets to be transferred in an optimal manner on shared links toward multiple destinations. We describe the mechanisms of the proposed scheme in establishing multicast tunnels within the network and performing group management. We explore the differences between the proposed scheme and the multimedia broadcast/multicast service of the 3GPP, and outline the advantages and disadvantages of both multicast schemes.     

Internet multicast routing and transport control protocols

Multicasting is a mechanism to send data to multiple receivers in an efficient way. We give a comprehensive survey on network and transport layer issues of Internet multicast. We begin with an introduction to the current Internet protocol multicast model-the "host group" model and the current Internet multicast architecture, then discuss in depth the following three research areas: (1) scalable multicast routing; (2) reliable multicast; and (3) multicast flow and congestion control. Our goal is to summarize the state of the art in Internet multicast and to stimulate further research in this area     

Security issues and solutions in multicast content distribution: a survey

Multicast enables efficient large-scale content distribution by providing an efficient transport mechanism for one-to-many and many-to-many communication. The very properties that make multicast attractive, however, also make it a challenging environment in which to provide content security. We show how the fundamental properties of the multicast paradigm cause security issues and vulnerabilities. We focus on four areas of research in security for multicast content distribution: receiver access control, group key management, multicast source authentication, and multicast fingerprinting. For each we explain the vulnerabilities, discuss the objectives of solutions, and survey work in the area. Also, we briefly highlight other security issues in multicast content distribution including source access control, secure multicast routing, and group policy specification. We then outline several future research directions.     

A survey of congestion control schemes for multicast video applications

Congestion control for IP multicast on the Internet has been one of the main issues that challenge a rapid deployment of IP multicast. In this article, we survey and discuss the most important congestion control schemes for multicast video applications on the Internet. We start with a discussion of the different elements of a multicast congestion control architecture. A congestion control scheme for multicast video possesses specific requirements for these elements. These requirements are discussed, along with the evaluation criteria for the performance of multicast video. We categorize the schemes we present into end-to-end schemes and router-supported schemes. We start with the end-to-end category and discuss several examples of both single-rate multicast applications and layered multicast applications. For the router-supported category, we first present single-rate schemes that utilize filtering of multicast packets by the routers. Next we discuss receiver-based layered schemes that rely on routers group?flow control of multicast sessions. We evaluate a number of schemes that belong to each of the two categories.     

Scalable reliable multicast using multiple multicast channels

We examine an approach for providing reliable, scalable multicast communication, involving the use of multiple multicast channels for reducing receiver processing costs and reducing network bandwidth consumption in a multicast session. In this approach a single multicast channel is used for the original transmission of packets. Retransmissions of packets are done on separate multicast channels, which receivers dynamically join and leave. We first show that protocols using an infinite number of multicast channels incur much less processing overhead at the receivers compared to protocols that use only a single multicast channel. This is due to the fact that receivers do not receive retransmissions of packets they have already received correctly. Next, we derive the number of unwanted redundant packets at a receiver due to using only a finite number of multicast channels, for a specific negative acknowledgment (NAK)-based protocol. We then explore the minimum number of multicast channels required to keep the cost of processing unwanted packets to a sufficiently low value. For an application consisting of a single sender transmitting reliably to many receivers we find that only a small number of multicast channels are required for a wide range of system parameters. In the case of an application where all participants simultaneously act as both senders and receivers a moderate number of multicast channels is needed. Finally, we present two mechanisms for implementing multiple multicast channels, one using multiple IP multicast groups and the other using additional router support for selective packet forwarding. We discuss the impact of both mechanisms on performance in terms of end-host and network resources     

Dynamic agent-based hierarchical multicast for wireless mesh networks

We propose and analyze a multicast algorithm named Dynamic Agent-based Hierarchical Multicast (DAHM) for wireless mesh networks that supports user mobility and dynamic group membership. The objective of DAHM is to minimize the overall network cost incurred. DAHM dynamically selects multicast routers serving as multicast agents for integrated mobility and multicast service management, effectively combining backbone multicast routing and local unicast routing into an integrated algorithm. As the name suggests, DAHM employs a two-level hierarchical multicast structure. At the upper level is a backbone multicast tree consisting of mesh routers with multicast agents being the leaves. At the lower level, each multicast agent services those multicast group members within its service region. A multicast group member changes its multicast agent when it moves out of the service region of the current multicast agent. The optimal service region size of a multicast agent is a critical system parameter. We propose a model-based approach to dynamically determine the optimal service region size that achieves network cost minimization. Through a comparative performance study, we show that DAHM significantly outperforms two existing baseline multicast algorithms based on multicast tree structures with dynamic updates upon member movement and group membership changes.     

Tracetree: a scalable mechanism to discover multicast tree topologies in the Internet

The successful deployment of multicast in the Internet requires the availability of good network management solutions. Discovering multicast tree topologies is an important component of this task. Network managers can use topology information to monitor and debug potential multicast forwarding problems. In addition, the collected topology has several other uses, for example, in reliable multicast transport protocols, in multicast congestion control protocols, and in discovering network characteristics. We present a mechanism for discovering multicast tree topologies using the forwarding state in the network. We call our approach tracetree. First, we present the basic operation of tracetree. Then, we explore various issues related to its functionality (e.g., scalability, security, etc.). Next, we provide a detailed evaluation by comparing it to the currently available alternatives. Finally, we discuss a number of deployment issues. We believe that tracetree provides an efficient and scalable mechanism for discovering multicast tree topologies and therefore fills an important void in the area of multicast network management.     

The evolution of multicast: from the MBone to interdomain multicastto Internet2 deployment

Multicast communication-the one-to-many or many-to-many delivery of data-is a hot topic. It is of interest in the research community, among standards groups, and to network service providers. For all the attention multicast has received, there are still issues that have not been completely resolved. One result is that protocols are still evolving, and some standards are not yet finished. From a deployment perspective, the lack of standards has slowed progress, but efforts to deploy multicast as an experimental service are in fact gaining momentum. The question now is how long it will be before multicast becomes a true Internet service. The goal of this article is to describe the past, present, and future of multicast. Starting with the Multicast Backbone (MBone), we describe how the emphasis has been on developing and refining intradomain multicast routing protocols. Starting in the middle to late 1990s, particular emphasis has been placed on developing interdomain multicast routing protocols. We provide a functional overview of the currently deployed solution. The future of multicast may hinge on several research efforts that are working to make the provision of multicast less complex by fundamentally changing the multicast model. We survey these efforts. Finally, attempts are being made to deploy native multicast routing in both Internet2 networks and the commodity Internet. We examine how multicast is being deployed in these networks     

A ring-based multicast routing topology with QoS support in wireless mesh networks

Wireless mesh networking (WMN) is an emerging technology for future broadband wireless access. The proliferation of the mobile computing devices that are equipped with cameras and ad hoc communication mode creates the possibility of exchanging real-time data between mobile users in wireless mesh networks. In this paper, we argue for a ring-based multicast routing topology with support from infrastructure nodes for group communications in WMNs. We study the performance of multicast communication over a ring routing topology when 802.11 with RTS/CTS scheme is used at the MAC layer to enable reliable multicast services in WMNs. We propose an algorithm to enhance the IP multicast routing on the ring topology. We show that when mesh routers on a ring topology support group communications by employing our proposed algorithms, a significant performance enhancement is realized. We analytically compute the end-to-end delay on a ring multicast routing topology. Our results show that the end-to-end delay is reduced about 33 %, and the capacity of multicast network (i.e., maximum group size that the ring can serve with QoS guarantees) is increased about 50 % as compared to conventional schemes. We also use our analytical results to develop heuristic algorithms for constructing an efficient ring-based multicast routing topology with QoS guarantees. The proposed algorithms take into account all possible traffic interference when constructing the multicast ring topology. Thus, the constructed ring topology provides QoS guarantees for the multicast traffic and minimizes the cost of group communications in WMNs.     

Domain Constrained Multicast: A New Approach for IP Multicast Routing

One of major reasons why IP multicast has not been well deployed is the complexity of IP multicast routing. Since existing IP multicast routing protocols have been designed independently of IP unicast routing protocols, a router must maintain routing tables for both IP mutlicast and unicast routing. This is, in particular, a big burden for an inter-domain router. In addition, by using existing IP multicast routing protocols, we cannot realize an application that a sending host outside the designated domain sends IP multicast packets only towards the designated domain. To resolve above issues, we propose a new architecture for IP multicast, which is called Domain Constrained Multicast (DCM). In this architecture, IP multicast packets are forwarded to a border router of the designated domain using IP unicast routing. And then, IP multicast packets are delivered inside the designated domain using IP multicast. We propose an address format when realizing the DCM architecture using IPv6. We describe the extension of the DCM architecture for applying it to inter-domain IP multicast routing. Finally, we have compared the DCM architecture for inter-domain routing, with existing inter-domain IP multicast routing protocols such as MSDP and BGMP.     

Algorithms for precomputing constrained widest paths and multicast trees

We consider the problem of precomputing constrained widest paths and multicast trees in a communication network. Precomputing and storing of the relevant information minimizes the computational overhead required to determine an optimal path when a new connection request arrives. We evaluate algorithms that precompute paths with maximal bandwidth (widest paths), which in addition satisfy given end-to-end delay constraints. We analyze and compare both the worst case and average case performance of the algorithms. We also show how the precomputed paths can be used to provide computationally efficient solutions to the constrained widest multicast tree problem. In this problem, a multicast tree with maximal bandwidth (widest multicast tree) is sought, which in addition satisfies given end-to-end delay constraints for each path on the tree from the source to a multicast destination.     

A case for end system multicast

The conventional wisdom has been that Internet protocol (IP) is the natural protocol layer for implementing multicast related functionality. However, more than a decade after its initial proposal, IP multicast is still plagued with concerns pertaining to scalability, network management, deployment, and support for higher layer functionality such as error, flow, and congestion control. We explore an alternative architecture that we term end system multicast, where end systems implement all multicast related functionality including membership management and packet replication. This shifting of multicast support from routers to end systems has the potential to address most problems associated with IP multicast. However, the key concern is the performance penalty associated with such a model. In particular, end system multicast introduces duplicate packets on physical links and incurs larger end-to-end delays than IP multicast. We study these performance concerns in the context of the Narada protocol. In Narada, end systems self-organize into an overlay structure using a fully distributed protocol. Further, end systems attempt to optimize the efficiency of the overlay by adapting to network dynamics and by considering application level performance. We present details of Narada and evaluate it using both simulation and Internet experiments. Our results indicate that the performance penalties are low both from the application and the network perspectives. We believe the potential benefits of transferring multicast functionality from end systems to routers significantly outweigh the performance penalty incurred.     

On the topology of multicast trees

The benefit derived from using multicast is seemingly dependent upon the shape of the distribution tree. We attempt to model interdomain multicast trees accurately. We measure a number of key parameters, such as depth, degree frequency, and average degree, for a number of real and synthetic data sets. We find that interdomain multicast trees actually do share a common shape at both the router and autonomous system levels. Furthermore, we develop a characterization of multicast efficiency which reveals that group sizes as small as 20 to 40 receivers offer a 55%-70% reduction in the total number of links traversed when compared to separately delivered unicast streams. A final contribution of our work consists in a number of data sets, compiled from multicast group membership and path data, that can be used to generate large sample trees, representative of the current multicast infrastructure.     

Minimum-cost multicast over coded packet networks

We consider the problem of establishing minimum-cost multicast connections over coded packet networks, i.e., packet networks where the contents of outgoing packets are arbitrary, causal functions of the contents of received packets. We consider both wireline and wireless packet networks as well as both static multicast (where membership of the multicast group remains constant for the duration of the connection) and dynamic multicast (where membership of the multicast group changes in time, with nodes joining and leaving the group). For static multicast, we reduce the problem to a polynomial-time solvable optimization problem, and we present decentralized algorithms for solving it. These algorithms, when coupled with existing decentralized schemes for constructing network codes, yield a fully decentralized approach for achieving minimum-cost multicast. By contrast, establishing minimum-cost static multicast connections over routed packet networks is a very difficult problem even using centralized computation, except in the special cases of unicast and broadcast connections. For dynamic multicast, we reduce the problem to a dynamic programming problem and apply the theory of dynamic programming to suggest how it may be solved.     

Investigation of multicast‐based mobility support in all‐IP cellular networks

To solve the IP mobility problem, the use of multicast has been proposed in a number of different approaches, applying multicast in different characteristic ways. We provide a systematic discussion of fundamental options for multicast‐based mobility support and the definition and experimental performance evaluation of selected schemes. The discussion is based on an analysis of the architectural, performance‐related, and functional requirements. By using these requirements and selecting options regarding network architecture and multicast protocols, we identify promising combinations and derive four case studies for multicast‐based mobility in IP‐based cellular networks. These case studies include both the standard any‐source IP multicast model as well as non‐standard multicast models, which optimally utilize the underlying multicast. We describe network architecture and protocols as well as a flexible software environment that allows to easily implement these and other classes of mobility‐supporting multicast protocols. Multicast schemes enable a high degree of flexibility for mobility mechanisms in order to meet the service quality required by the applications with minimal protocol overhead. We evaluate this overhead using our software environment by implementing prototypes and quantifying handoff‐specific metrics, namely, handoff and paging latency, packet loss and duplication rates, as well as TCP goodput. The measurement results show that these multicast‐based schemes improve handoff performance for high mobility in comparison to the reference cases: basic and hierarchical Mobile IP. Comparing the multicast‐schemes among each other the performance for the evaluated metrics is very similar. As a result of the conceptual framework classification and our performance evaluations, we justify specific protocol mechanisms that utilize specific features of the multicast. Based on this justification, we advocate the usage of a source‐specific multicast service model for multicast‐based mobility support that adverts the weaknesses of the classical Internet any‐source multicast service model. Copyright © 2006 John Wiley & Sons, Ltd.     

An Efficient Multicast Routing Protocol in Wireless Mobile Networks

Providing multicast service to mobile hosts in wireless mobile networking environments is difficult due to frequent changes of mobile host location and group membership. If a conventional multicast routing protocol is used in wireless mobile networks, several problems may be experienced since existing multicast routing protocols assume static hosts when they construct the multicast delivery tree. To overcome the problems, several multicast routing protocols for mobile hosts have been proposed. Although the protocols solve several problems inherent in multicast routing proposals for static hosts, they still have problems such as non-optimal delivery path, datagram duplication, overheads resulting from frequent reconstruction of a multicast tree, etc. In this paper, we summarize these problems of multicast routing protocols and propose an efficient multicast routing protocol based on IEFT mobile IP in wireless mobile networks. The proposed protocol introduces a multicast agent, where a mobile host receives a tunneled multicast datagram from a multicast agent located in a network close to it or directly from the multicast router in the current network. While receiving a tunneled multicast datagram from a remote multicast agent, the local multicast agent may start multicast join process, which makes the multicast delivery route optimal. The proposed protocol reduces data delivery path length and decreases the amount of duplicate copies of multicast datagrams. We examined and compared the performance of the proposed protocol and existing protocols by simulation under various environments and we got an improved performance over the existing proposals.     

A multicast mechanism for mobile multimedia messaging service

Based on the cell broadcast service architecture, this paper proposes an efficient multicast mechanism for the universal mobile telecommunications system to support multimedia messaging service (MMS). We define a new interface between the serving GPRS support node and the cell broadcast center to track the current locations of the multicast members. Then we describe the location tracking procedures (including attach, detach, and location update) of the multicast members and the multicast message delivery procedure. We use an analytic model to investigate the performance of our approach. This paper indicates that our MMS multicast mechanism outperforms the previous proposed approaches.