Transcript Director: Sheng-Wei Chen Presenter: Shun-Yun Hu MMNet Intro  Multimedia Networking and Systems Laboratory  Established since 2006.  Dr.

Director: Sheng-Wei Chen
Presenter: Shun-Yun Hu
MMNet Intro
 Multimedia Networking and Systems Laboratory
 Established since 2006.
 Dr. Sheng-Wei Chen (Associate Fellow)
 Postdoc (1), Ph.D (5), RA (10)
 Main Research Areas:
 Internet Quality of Experience (QoE)
 Network Security
 Online Gaming
Research Areas
• Internet Quality of Experience (QoE)
• User satisfaction index & framework
• Packet rate adjustment for efficiency
• Network Security
• Quantify info leakage on social networks
• Phishing detection
• Online Gaming
• Efficient data transmission
• Game bots detection
Blizzard, World of Warcraft
America’s Army
Forterra Systems
Can we build a virtual environment with
millions of concurrent users?
Spatial publish subscribe (SPS)
Point publication
Area publication
Point subscription
Area subscription
pub
sub
Na
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n
a
l
C
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t
r
a
l
U
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i
v
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r
s
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t
y
A simple solution (point-to-point)
Source: [Funkhouser95]
But…too many irrelevant messages
N * (N-1) connections ≈ O(N2)  Not scalable!
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A better solution (client-server)
Source: [Funkhouser95]
Message filtering at server to reduce traffic
N connections = O(N)  server is bottleneck
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Current solution (server-cluster)
Source: [Funkhouser95]
How to partition & balance load?
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Load fluctuations
Density-aware Partitioning
Na
t
i
o
n
a
l
neighbors for
C
e
n
Non-overlapped
t
neighbors
r
a
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U
n
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v
e
r
s
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t
y
Voronoi-based Overlay Network (VON)
Voronoi diagrams identify boundary
neighbor discovery
Boundary
neighbors
New
neighbors
20/
Dynamic Load Balancing
Overlap in neighbor regions
J
K
L
I
B
M
A
C
root
N
H
E
G
D
O
F
P
Q
Conclusion
 Potential Applications
 Voice communication
 3D content streaming
 State management
 Future Works
 Area publications
 Experiment with millions of entities
 Cloud & P2P deployment
References
[1] Shun-Yun Hu, Jui-Fa Chen and Tsu-Han Chen, "VON:
A scalable peer-to-peer network for virtual
environments," IEEE Network, vol. 20 no. 4, Jul./Aug.
2006, pp. 22-31.
[2] Yeng-Ting Lee and Kuan-Ta Chen, “Is Server
Consolidation Beneficial to MMORPG? A Case Study of
World of Warcraft,” in Proc. IEEE Cloud, 2010.
[3] Shun-Yun Hu and Kuan-Ta Chen, "VSO: Selforganizing Spatial Publish Subscribe," in Proc. Fifth
IEEE Self-Adaptive and Self-Organizing Systems
(SASO 2011), Oct. 2011.
Thank You
Q&A
Static vs. dynamic partitioning
Effect of churn on consistency
Voronoi Diagram
2D Plane partitioned into regions by sites, each region
contains all the points closest to its site
Neighbors
Region
Site
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Design Concepts
Use Voronoi to solve the neighbor discovery problem
Identify enclosing and boundary neighbors
Boundary neighbors mutually help to discover neighbors
Circle
Area of Interest (AOI)
White
self
Yellow
enclosing neighbor (E.N.)
L. Blue
boundary neighbor (B.N.)
Pink
E.N. & B.N.
Green
normal AOI neighbor
L. Green unknown neighbor
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