Flow and Congestion Control: Avoiding Overuse of User and Network Resources

Summary

Flow and congestion control schemes are employed to protect end users, network entities, and system resources from being overloaded by message flows. Under a closed‐loop flow control (FC) scheme, the sending entity regulates the rate at which it sends messages to a destination entity based on feedback signals that it receives from the destination entity. Under an open‐loop FC scheme, the sending entity adjusts the message traffic flow pattern that it uses to send to the network so that it conforms with an imposed or negotiated traffic boundary pattern. Dynamically adaptive schemes make use of ongoing congestion monitoring techniques to adjust FC regulations at end users and at internal network entities. The chapter describes several reactive and proactive congestion control methods. It is essential to implement proactive congestion control schemes that forecast congestion trends and act promptly to eliminate congestion bottlenecks.