Implicit SIP proxy overload detection mechanism based on response behavior

Detecting overload in telecommunication networks is an important goal, because it allows to react on it and to reduce traffic smartly to ensure constant user experienced quality of service. This applies not only to media as voice and video, but also to signaling, which is responsible for setting up these media. An overloaded signaling network increases the response delay and reduces the successfully processed service requests and therefore the revenue. We propose an implicit overload detection mechanism for SIP networks that allows detecting overloaded components by their response behavior. This mechanism realizes maximum throughput with marginal response delay increase in the case of congestion without protocol modifications or extensions and therefore ensures proper operation of SIP networks in case of overload.