A Congestion Control Algorithm for Signalling Networks Based on a State Machine Controlled by Network Delays

Congestion control in Signaling System number 7 faces new challenges as mobile communication systems and Intelligent Networks grow rapidly. New services change traffic patterns, add to signalling network load, and raise demands on shorter service completion times. To handle new demands, the congestion control mechanisms must foresee an overload situation, and respond to it so that the network can maintain high throughput. With the introduction of a state machine and a memory function for each signaling link it is possible to predict the completion time of a service session and to detect an emerging congestion. If the predicted completion time of a service session is too long, the session is annihilated. This is the foundation of a congestion control mechanism that reacts fast on information supplied by the network. The congestion control mechanism enables the network to maintain a high throughput during overload.