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ABSTRACT IP is the natural protocol layer for implementing multicast related functionality IP Multicast is still plagued with concerns pertaining to scalability network management deployment The explore an alternative architecture for small and sparse groups where end systems implement all multicast related functionality including membership management and packet replication 3
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A Case for End System Multicast
學號: 96325523報告人:通訊所 吳瑞益指導教授:楊峻權日期: 2009.04.30
2000 ACM SIGMETRICS
OUTLINE
1. ABSTRACT2. INTRODUCTION3. NARADA DESIGN4. SIMULATION RESULT 5. CONCLUSIONS
2
ABSTRACT• IP is the natural protocol layer for implementing
multicast related functionality• IP Multicast is still plagued with concerns
pertaining to scalability network management deployment
• The explore an alternative architecture for small and sparse groups where end systems implement all multicast related functionality including membership management and packet replication
3
1.INTRODUCTION
4
End Systems
Routers
Gatech
CMU
Stanford
Berkeley
- Unicast Transmissiont
1.INTRODUCTION
5
- IP Multicast
5
•No duplicate packets•Highly efficient bandwidth usage
Berkeley
Gatech Stanford
CMU
Routers with multicast support
1.INTRODUCTION
6
- End System Multicast 1
6
Stanford
CMU
Stan1
Stan2
Berk2
Overlay Tree
Gatech
Berk1
Berkeley
Gatech Stan1
Stan2
Berk1
Berk2
CMU
1.INTRODUCTION
7
- End System Multicast 2
3.NARADA DESIGN
8
3.NARADA DESIGN (con.)
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Step 1
•Source rooted shortest delay spanning trees of mesh•Constructed using well known routing algorithms
– Members have low degrees– Small delay from source to receivers
“Mesh”: Richer overlay that may have cycles and includes all group members
• Members have low degrees• Shortest path delay between any pair of members along mesh is small
Step 2
3.NARADA DESIGN(con.)1. Group Management
– Member Join– Member Leave and Failure
2. Repairing Mesh Partitions3. Improving mesh quality
– Addition of links– Dropping of links
4. Data Delivery
10
4.SIMULATION RESULT - INDICES
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RDP = Relative Delay PenaltyThe ratio of the delay between two members along the overlay to the unicast delay between them
Ex : (show in figure(f) at Page-6)
<A,D> = 29/27<A,C> and <A,B> = 1
4.SIMULATION RESULT - RDP
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4.SIMULATION RESULT - STABLIZE
13
5.CONCLUSIONS
14
• Proposed in 1989, IP Multicast is not yet widely deployed– Per-group state, control state complexity and scaling concerns– Difficult to support higher layer functionality– Difficult to deploy, and get ISP’s to turn on IP Multicast
• For small-sized groups, an end-system overlay approach – is feasible– has a low performance penalty compared to IP Multicast– has the potential to simplify support for higher layer
functionality– allows for application-specific customizations