Delay, throughput, and fairness are three conflicting performance criteria in modern flow controlled communication networks. This paper investigates the interrelationships of those three performance criteria and defines an “optimal tradeoff” among them. To this aim, several fair bandwidth sharing schemes are introduced and compared each other for a variety of network configurations. The results obtained are then utilized to define the optimal operating point (OOP) which maximizes the generalized network power. Given a fixed routing, it is shown that the OOP can be found via any unconstrained optimization algorithm. If rerouting is allowed, it is also shown that the OOP can be found by solving a variant of multicommodity convex cost network flow problem. An algorithm for this problem is developed and tested for a number of networks. Finally, a delay-directive flow control scheme is suggested to realize the OOP in real operating networks and some discussions are made on additional implementation issues.