PCP a Savior or a Saboteur?

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PCP a Savior or a Saboteur?

• Presented by Ao-Jan Su

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New, is NOT necessarily Good!!
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Accuracy

• Probe results accuracy?
• PCPs probe test is similar to pathload Jain and
  Dovrolis
• pathload underestimates the available bandwidth
  when there are multiple tight link
• Longer paths suffer more
• Clock Skew?
• Timestamp is recorded at the receiver!

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Efficiency

• Criteria for Selecting Controls
• Efficiency, Fairness, Distributedness and
  Convergence AIMD paper
• Lack for link utilization analysis in the paper
• Cant avoid oscillation

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Overhead

• What is the impact of probe packets to the
  network?
• Periodic probes
• Proportional to the number of flows
• For short (web) traffic, the overhead can be
  significant

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Security

• Also not mentioned in the paper
• End hosts are easier to compromise than routers
• Encourages DDoS attack