Uplink Allocation Beyond Choke Unchoke or How to Divide and Conquer Best

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Uplink Allocation Beyond Choke / Unchokeor How
to Divide and Conquer Best

• Nikolaos Laoutaris (Damiano Carra Pietro
  Michiardi), Damiano Carra(INRIA - Sophia
  Antipolis ) and Pietro Michiardi (Eurecom)
• , Presented by Haiyang Wang

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The objective of this paper

• Shorten the downloading time of BitTorrent by
  improving the uplink utilization of nodes in the
  cooperative environment.

• Piece selection
• Local rarest first
• Peer selection
• Peers Chocking algorithm

Peers

• Every 10s, unchoke 4 peers according to their
  uploading bandwidth
• Every 30s, unchoke 1 random peer

Tracker
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The main argument of this paper

• Why we have to unchoke 4 peers? Why we have to
  serve these 4 peers equally?

• Some similar arguments
• Improving BitTorrent a Simple Approach by
  Alix L.H. Chow et al. in IPTPS 08
• Why seeders have to serve all kinds of leechers?
• Small Is Not Always Beautiful from by Pawe
  Marciniak et al. in IPTPS 08
• Why we have to use small pieces in BT?

• The feature point of this paper
• BT uploading problem in the cooperative
  environment.
• Do incentives build robustness in BitTorrent?
  by Michael Piatek et al. in NSDI'07

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The partition of upload bandwidth

• If the seeder is trying to deliver a single piece
• The probability of x peers can get this piece in
  round i is P(xn(i))
• Number of peers that have the piece in the i1th
  round

K partition U uploading
bandwidth
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Bitmax uplink allocation

• The authors formulate the uplink allocation
  problem into the fractional knapsack problem.
• U(vi, h)/W(vi)
• They give two utility functions

Ranking-Based Optimal Resource Allocation in
Peer-to-Peer Networks in INFOCOM 07
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Selected evaluation results

• Simulation based evaluation (GPS- General
  Peer-to-Peer Simulator for BT)

500 peers
100 peers
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Selected evaluation results

• Simulation based evaluation(GPS- General
  Peer-to-Peer Simulator for BT)

BitMax1
BitMax2
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Conclusion

• A study focused on BT Uploading problem in
  cooperative environment.
• The approach is based on utility maximization.
• This approach tries to focus instead of
  over-curve the uplink of BT peers

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Some Discussions
1 Single piece analysis 2 One
direction based analysis
P1
P1
P2
A
A
B
C
B
C