Resource pricing and the evolution of congestion control

Resource pricing and the evolution of congestion control By R. J. Gibbens and F. P. Kelly

A proportionally fair pricing. A fair distribution according to a price the user is willing to pay. Why ? How ?

Rates according to shadow pricing • Let • Then The change in the rate is:

Rates according to shadow pricing • If w(t) = wr Then the stable point of the system is : A proportionally fair per unit charge.

Congestion Mechanisms • Creating various measurements and congestion control algorithms in the network itself (routers). [floyd and fall] • Creating incentives for the end nodes to use congestion control – charge aware TCP

Different approaches to charge aware TCP • Paris metro pricing • Smart market

The Expected Cost and Shadow price

The Expected Number of marks

When distribution is more general Thus

Congestion Algorithm 1 the Elastic User(w) Where

Congestion algorithm 2 File Transfer(F, W) Elastic User that changes the Payment.

Comparison with the Internet Packet conversation principle A new packet isn’t put into the network until the old packet leaves = self clocking

Current congestion algorithm disadvantages • Not user specific. • Dropping packages is an extreme mechanism for congestion control. • The rate at which the signals a generated in the source.

Response of end-nodes to Congestion • Jacobson – Average Rate • Elastic user - Inverse proportion to

Jacobson Average Rate in our Equations • If the user needs the average rate of Jacobson than the utility function would produce that rate.

Self Clocking in our Equations When no congestion indications are present File-transfer is doubling it’s rate (with proportion to T).

Self Clocking in our Equations • Elastic User can be self clocking if cwnd increased by • So the change in the rate is :

Game Theory Model • If the user is price-aware he will maximize: • The solution is When

Game Theory The average paying is When r= is constant and equal Then Conclusion – users shade their bids if they have market power

Concluding remarks By appropriately marking the resources end-nodes are provided with the necessary information to make efficient use of the network resources