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The Research On QoS-based Multicast Routing Techniques In Internet

Posted on:2007-09-01Degree:DoctorType:Dissertation
Country:ChinaCandidate:X YanFull Text:PDF
GTID:1118360185984531Subject:Traffic Information Engineering & Control
Abstract/Summary:PDF Full Text Request
QoS-based multicast routing technique is the key to apply multimedia operations in Internet. However, so far there remain many problems still expecting to be solved in the field of QoS-based multicast routing. Surrounding the two themes, NP-completeness and state information imprecision, this dissertation undertakes an in-depth study of some key issues in the field, including multiple QoS constraints, imprecise network state, ACO (Ant Colony Optimization) application, and routing scalability etc. The following work is accomplished in this dissertation.1) At first, a network simulation platform is necessary in order to analyze and validate the protocols or algorithms proposed in this thesis. However, the current network simulators aren't able to satisfy our requirements for simulating network dynamics and QoS routing. Therefore, the state update model of NS2 is modified in this thesis by using a triple hybrid update model to take the place of it, and several new traffic generators are added to the traffic model of NS2. And that, this dissertation extends the link object of NS2 so that it's able to detect and control QoS metrics on it. Eventually, a network simulator based on NS2, DRS, which can simulate network dynamics and imprecise state information efficiently, and support QoS routing, with a topology simulator Top-Builder, is designed in this thesis. This topology simulator integrates some worthy functions of the existing various topology simulators. It's able to not only accurately represent various topologies of Internet but also facilely construct experimental topologies, as well as it has a good scalability.2) The existing QoS multicast routing algorithms don't take into account the impact of the imprecision of network state information on routing performance. This dissertation proposes a novel model that represents the imprecision of state information by the assumption of a probability distribution. On the basis of the probability model, a distributed multicast routing algorithm with multiple QoS constraints, called QMRI, which solves the NP-complete problem in manner of a distributed computation based on the traffic light mode, is presented in this thesis. Experimental results show that QMRI not only can tolerate the high degree of state information imprecision, but it also achieves a high call-admission ratio with a modest message overhead.
Keywords/Search Tags:QoS routing, multicast routing, Internet, network simulation, imprecise state, hierarchical routing
PDF Full Text Request
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