PCP a Savior or a Saboteur? Presented by: Ao-Jan Su

New, is NOT necessarily Good!! TCP, Vegas, RAP, Fast TCP, S-TCP High Speed TCP DecBit, ECN, RED, AQM PCP ATM, XCP, WFQ, RCP End PointRouter Support Try and Backoff Request and Set Not Accurate Not Secure Additional Overhead

Accuracy Probe results’ accuracy? –PCP’s 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!

Efficiency Criteria for Selecting Controls –Efficiency, Fairness, Distributedness and Convergence [AIMD paper] Lack for link utilization analysis in the paper Can’t avoid oscillation

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

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