Efficient Micro-Mobility using Intra-domain Multicast-based Mechanisms (M&M)

One of the most important metrics in the design of IP mobility protocols is the handover performance. The current Mobile IP (MIP) standard has been shown to exhibit poor handover performance. Most other work attempts to modify MIP to slightly improve its efficiency, while others propose complex techniques to replace MIP. Rather than taking these approaches, we instead propose a new architecture for providing efficient and smooth handover, while being able to co-exist and inter-operate with other technologies. Specifically, we propose an intra-domain multicast-based mobility architecture, where a visiting mobile is assigned a multicast address to use while moving within a domain. Efficient handover is achieved using standard multicast join/prune mechanisms. Two approaches are proposed and contrasted. The first introduces the concept proxy-based mobility, while the other uses algorithmic mapping to obtain the multicast address of visiting mobiles. We show that the algorithmic mapping approach has several advantages over the proxy approach, and provide mechanisms to support it. Network simulation (using NS-2) is used to evaluate our scheme and compare it to other routing-based micro-mobility schemes - CIP and HAWAII. The proactive handover results show that both M&M and CIP shows low handoff delay and packet reordering depth as compared to HAWAII. The reason for M&M's comparable performance with CIP is that both use bi-cast in proactive handover. The M&M, however, handles multiple border routers in a domain, where CIP fails. We also provide a handover algorithm leveraging the proactive path setup capability of M&M, which is expected to outperform CIP in case of reactive handover.Comment: 12 pages, 11 figure

THE COMPLEXITY OF RP SELECTION IN MULTICAST CHANNELIZATION

Rendezvous point (RP) selection for multicast groups is the problem of selecting a node to serve as the RP-host for a multicast group. We consider rendezvous point selection in the context of channelization where groups have been established based on user preferences for a set of available flows. Thus, each of the flows associated with a group will arrive at the node that serves as the RP-host for that group, from which those flows will be multicast to the group subscribers. We study the simultaneous assignment of RP-hosts for a collection of multicast groups with the dual goals of a) not overloading any single node serving as a host; and, b) minimizing the total network traffic. Toward those ends we consider two versions of the problem. For Bounded Host Assignment, we give a polynomial time algorithm for finding an optimal assignment. For Host Traffic Constrained Assignment, we establish that the problem is NP-complete and then study approximation algorithms. Simulation results are provided for the latter problem comparing the effectiveness of the solutions produced by our algorithms with optimal solutions

Managing dynamic groups in QoS and overlay multicasting

Multicasting has been the most popular mechanism for supporting group communication, wherein group members communicate through a multicast data distribution tree that spans all the members of the group. In a dynamic multicast session, members join/leave the group using graft/prune mechanisms, based on locally optimal paths, which would eventually degenerate the quality of the multicast tree. Therefore, efficient mechanisms need to be invoked periodically to maintain the cost of the multicast tree near optimal. However, tree maintenance would result in service disruption for the session. Therefore, there exists a trade-off between minimizing tree cost and minimizing service disruption. The goal of this dissertation is to develop and analyze a set of efficient tree maintenance techniques that aim to balance this tradeoff in QoS and overlay multicasting. To achieve this goal, the dissertation makes three key contributions. First, the design of scalable protocols, viz. tree migration and tree evolution, for maintaining QoS multicast trees. Second, the design of an efficient strategy, called partial protection approach, and its implementation methods for member join problem with path reliability being a QoS constraint. Third, the design of an efficient tree maintenance algorithm, based on the idea of mesh-tree interactions, for end-system based overlay multicasting. The proposed tree maintenance solutions have been evaluated and analyzed through a combination of simulation and analytical studies. The studies show that the proposed solutions indeed achieve a good balance between tree cost and service disruption competitively

Quality of service (QoS) support for multimedia applications in large-scale networks

This dissertation studied issues pertaining to QoS provision for multimedia applications at the application layer. We initially studied Internet routing pathology and Internet routing stability by repeating experimental and analytical methods conducted by Paxson in 1996. No similar study was done in recent years. Our findings show that routing behavior of the Internet in 2006 are different from those reported in 1996 in some important aspects. Second, we investigated different stochastic models (e.g. self-similar processes, Auto-Regressive Integrated Moving-Average (ARIMA)) in order to find a suitable model that describes available bandwidth over time of an end-to-end path between two Internet hosts. Our finding of the suitable model is beneficial to predicting of future values of available bandwidth along an end-to-end path. To the best of our knowledge, no similar study was conducted. Third, we designed and evaluated a new path monitoring algorithm inferring available bandwidth of an end-to-end path without monitoring all the paths to minimize monitoring overhead. Our algorithm does not rely on underlying network-layer topology information as required in topology-aware path monitoring techniques. Finally, to complement the above study, we introduced our multicast protocol named core-set routing for transmitting multimedia data from a set of senders to a set of receivers, taking QoS into account. The protocol is suitable for interactive multi-sender multimedia applications such as video conferencing and network gaming

On the performance and feasibility of multicast core selection heuristics

Article dans revue scientifique avec comité de lecture.A core-based forwarding multicast protocol uses a core router as a traffic transit center : all multicast packets are first sent to the core, then distributed to destinations on a multicast tree rooted at the core. The purpose of this paper is to evaluate, via simulation, the effect of various core selection methods on multicast performances. Performances metrics of interest include network ressource usage, packet delay, the join time of multicast participants and link congestion. In addition we assess the feasability of these heuristics in real-world environments