Patent ID: 6633539
Filing Date: 2003-10-14
Classification: H04L

Abstract:
A method to prevent signaling congestion in a connection-oriented network node comprising the steps of:a) predefining a threshold number (Max) as the maximum number of allowed call set up messages (CSMs) to be processed from a plurality of sources by the network node and predefining a time frame window as the time within which no more than the threshold number (Max) CSMs are accepted for processing by the network node for processing; b) detecting each new incoming CSM in the network node; c) rejecting each new incoming CSM if the number of CSMs currently being processed by the network node equals the threshold number (Max); or the number of CSMs accepted for processing during the current time frame window equals the threshold number (Max); d) accepting each new incoming CSM that is not rejected; e) filtering each new incoming CSM to determine whether said CSM satisfies at least one predefined filtering criterion, and accepting said incoming CSM if it does not satisfy any of said at least one predefined criterion, or proceeding further with the steps of c) and d) otherwise; f) incrementing a counter (CNT) each time an incoming CSM which has satisfied said at least one predefined criterion and was previously accepted for processing; g) decrementing said counter (CNT) each time an acknowledgement message which concerns a CSM which has satisfied said at least one predefined criterion and was previously accepted for processing; h) comparing the current value of said counter (CNT) to said threshold number (Max) to determine whether said incoming CSM should be rejected or processed further; and i) flagging in a memory table each accepted CSM that has satisfied said at least one predefined criterion, whereby each time an acknowledgement message is received, it is determined whether said counter (CNT) should be decremented.