Peertopeer Multimedia Streaming and Caching Service

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Peer-to-peer Multimedia Streaming and Caching
Service

• Jie WEI, Zhen MA
• May. 29

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Outline

• Metrics For Multimedia Streaming
• Non P2P Solution
• Peer to Peer Solution
• Architecture
• Caching
• Streaming
• Conclusion

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Metrics For Multimedia Streaming

• Low initial Delay
• Small Delay Jitter During Playback
• Minimum network bandwidth utilization

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Non P2P Solution

• Caching and Pre-fetching by Media Gateway
• Achieve small initial delay and delay jitter
  during playback
• Broadcasting Services
• Achieve minimum server network bandwidth
  utilization

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Motivation For P2P Architecture

• Motivation of the peer-to-peer architecture
• Exploits the proximity of clients
• Minimizes the bandwidth utilization between the
  server and group of clients
• Architecture
• Assumes the group of peer-to-peer clients is
  connected via LAN
• Each client not only receives streams from the
  server, but also acts as a proxy server.

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Architecture

• One server,one cache manager and four nodes
• s(i,j) represents segment of stream between byte
  i and j

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Caching Management

• Each client caches the retrieved stream and
  publishes its cache information to the cache
  manager
• Each client monitors its own resource
  availability (eg. network bandwidth), updates all
  information to the cache manager

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Streaming

• Cache lookup
• Send query message to cache manager for
  information of cached streams in peer clients
• Streaming and Pre-fetching
• With response from the cache manager, the client
  send streaming and pre-fetching requests to the
  peer clients or the server

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Streaming

• Timing diagram of the streaming and pre-fetching
  (requested by Ci)

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Streaming Switching

• In order to minimize the switching delay jitter,
  we should ensure a proper pre-fetching time
• The pre-fetching time t is determined by,
• Network bandwidth B
• Network delay D

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Pre-fetching Time

• Case 1 B is larger than requested service rate,
  we only need to care about the network delay to
  ensure proper pre-fetching
• Case 2 B is smaller than ?, Buffer underflow
  might happen. We need to consider both network
  bandwidth and delay to ensure proper pre-fetching

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How it achieves the metrics

• Low initial Delay?
• Small Delay Jitter During Playback?
• Minimum network bandwidth utilization?

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How it achieves the metrics

• Low initial Delay
• By requesting to a peer client in the peer
  group, which caches the initial segments, it
  lowers initial delay than always requesting
  directly to the distant server

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How it achieves the metrics

• Small Delay Jitter During Playback?
• Minimize the switching delay jitter by
  calculating the right time point to do enough
  pre-fetching

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How it achieves the metrics

• Minimum network bandwidth utilization?
• P2P architecture reduces network bandwidth
  utilization and stream transfer time in the
  Client-Server architecture

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Conclusion

• Discussed a P2P Multimedia Streaming and Caching
  Model
• P2P Multimedia Streaming and Caching Service can
  improve performance in all the three metrics.

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Thank you