transcript
- Slide 1
- Chun-Yuan Chang, Cheng-Fu Chou * and Ming-Hung Chen Presenter:
Prof. Cheng-Fu Chou National Taiwan University
ccf@cmlab.csie.ntu.edu.tw
- Slide 2
- Introduction Model & Chunk Selection Strategies Practical
P2P Streaming System & Dynamic Strategy-Switch Performance
Evaluation Conclusion
- Slide 3
- Swarm-Based P2P Streaming Similar to BitTorrent Encourage users
to contribute its outbound bandwidth and storage to speed up
content distribution. PPLive, PPStream, CoolStreaming and
GridMedia, etc
- Slide 4
- Two components Overlay construction Chunk swarming mechanism
Buffer map exchange Chunk scheduling The chunk IDs the peer
possesses
- Slide 5
- Content bottleneck problem No content to exchange even if
outbound bandwidth is sufficient More diverse the content
distribution is made, the less the content bottleneck is !!
- Slide 6
- Existing approaches Rarest-First E.g. CoolStreaming Infocom
2005 Random E.g. Chainsaw Infocom 2005 Hybrid ones (Deadline-First
+ Rarest-First) E.g. Bitos Infocom 2006 and Prime Infocom 2007
Network Coding E.g. R2 JASC 2007
- Slide 7
- System dynamics Peer churn Network core congestion Variable
source streaming rate Content diversity Random chunk loss Content
Importance Unequal content importance
- Slide 8
- With and without considering content importance
- Slide 9
- Introduction Model & Chunk Selection Strategies Practical
P2P Streaming System & Dynamic Strategy-Switch Performance
Evaluation Conclusion
- Slide 10
- Simple Model (ICNP 2007)
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- Recursive Formulation
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- Priority B(1)>B(2).. therefore
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- c h > c l Rarity is adopted to do a tie-break
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- Only c h can compete to each other
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- ComparisonScheduling efficiency Content Bottleneck IFGoodHigh
RFPoorLow How can we support high scheduling Efficiency and
maintain the scalability at the same time?
- Slide 20
- When population size is not large, we can enjoy throughput and
scheduling efficiency simultaneously There exist a good balance
between content diversity and content importance
- Slide 21
- Introduction Model & Chunk Selection Strategies Practical
P2P Streaming System & Dynamic Strategy-Switch Performance
Evaluation Conclusion
- Slide 22
- Receiver Side
- Slide 23
- Supplier Side
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- As a receiver: Detect if the number of retrieval chunks in the
request window is zero. If it does, send a signal to itself. No
scheduling process will be performed. If it does not, just
subscribe to all desired chunks and assign each desired chunk to a
peer who possesses the chunk in a random fashion As a sender: Check
if the event of content bottleneck is captured. If it does, conduct
RAND on each requested packet. Otherwise, conduct IF on each
requested packet.
- Slide 25
- Introduction Model & Chunk Selection Strategies Practical
P2P Streaming System & Dynamic Strategy-Switch Performance
Evaluation Conclusion
- Slide 26
- Simulator GridMedia Project Settings:
- Slide 27
- Video Trace: Encoded by H.264 (JM16.0) Concatenated by
different types of CIF video sequences, which include high motion
and low motion video sequences Fixed the quantization parameters
(QP) for I,P,B frame in encoding
- Slide 28
- Delivery Ratio: the ratio of the number of chunks that arrive
before playback deadline to the number of chunks that should arrive
before playback deadline. PSNR (dB): the rendered video quality
compared with the raw video sequence. The ffmpeg is used as our
decoder.
- Slide 29
- RAND: peers always serve the chunk in random fashion IF-IPB:
peers always serve the chunk with highest priority with respect to
IPB. PR-IPB: the prioritized random scheduling in [10] UL-IPB: the
utility-like approach in [15]
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- Scalability
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- Scheduling Efficiency
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- PSNR over time with 4,500 peers underloadoverload
- Slide 33
- Point out the trade-off between content diversity and content
importance A simple but effective content bottleneck detector is
proposed to strike the balance between content diversity and
content importance