Multicast With Network Coding in ApplicationLayer Overlay Network

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Multicast With Network Coding in
Application-Layer Overlay Network

• Ying Zhu, Baochun Li, Jiang Guo
• Presented by Koji Lin_at_netlab

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Outline

• Introduction
• A case for App-Layer Coded Multicast
• Preliminaries
• Algorithm Analysis
• Performance Evaluation
• Related Work Conclusion

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Introduction

• Why App-Layer multicast?
• Multicast support is not required
• Data is transmitted via unicast
• Effectively exploiting security, flow control,
  reliable
• Disadvantages
• Link stress stretch

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Introduction (cont.)

• Deviating from the conventional App-Layer
  multicast
• Applying the network coding
• Topology is not a tree
• Constructing a 2-redundant multicast graph

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A case for App-Layer Coded Multicast

• Main Contribution
• Multiple data paths
• Concept of network coding in App-Layer multicasts
• Objectives
• Taking advantage of alternative path excess
  capacity in the IP-layer network

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A case for App-Layer Coded Multicast

• What will happen to the tree topology?
• The gain may be overshadowed by the cost
• Must ensure that the alternative paths dont
  conflict with the original path, But Its really
  hard

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A case for App-Layer Coded Multicast
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A case for App-Layer Coded Multicast
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A case for App-Layer Coded Multicast
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A case for App-Layer Coded Multicast
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Preliminaries

• Individual Maxflow
• Simultaneous Maxflow
• k-Redundant Multicast Graph
• s, u, t
• outdegree(s) gt 0, indegree(s) 0
• 1 lt indegree(u) lt k, 0 lt outdegree(u)
• indegree(t) k, 0 lt outdegree(u)

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Preliminaries

• Disjoint Paths
• Linear Coding Multicast
• Let Simultaneous maxflow ti is equal to
  individual maxflow of ti

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Algorithm Analysis

• Non Trivial Challenges
• Correctly constructing a 2-redundant graph
• Minimizing the number of intermediate nodes
• Minimizing stress for maximizing performance

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Algorithm Analysis
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Algorithm Analysis

• Mainly three steps
• Building a relatively densely connected graph ,
  referred to as the rudimental graph.
• Building a spanning tree of only the intermediate
  nodes with source S , referred to as the
  rudimental tree
• Constructing the 2-redudant multicast graph

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Algorithm Analysis
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Algorithm Analysis
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Algorithm Analysis
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Algorithm Analysis
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Algorithm Analysis
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Algorithm Analysis
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Algorithm Analysis

• Control overhead
• Worse O(logn)
• Resorting to existing flow control mechanism
• Complexity Analysis of Linear Algorithm
• The total number of control messages transmitted
  for is O(n)
• Overall time complexity is O(T)
• T denote the largest delay from s to any node in
  graph

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Performance Evaluation
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Performance Evaluation
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Performance Evaluation
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Performance Evaluation
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Performance Evaluation
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Related Work Conclusion

• Multiple path has been studied in the area of QOS
  routing
• Other tree topologies
• Just one source
• Providing flexibility and efficiency

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Related Work Conclusion

• Significantly improving end-to-end multicast
  session throughput
• Not exist similar proposals in previous
  literatures
• Implementing on testbed PlanetLab