Congestion control in an IP network

摘要

Upon detection of an overload condition at a network element, the network element sends two messages to those other network elements which may potentially send request messages to the overloaded network element. If the network utilizes the SIP signaling protocol, then the messages sent by an overloaded network element are SIP INVITE and SIP CANCEL. The CANCEL message comprises an indication that the sending network element is unavailable and an amount of time which the recipient network elements are to wait before sending any requests to the overloaded network node. Upon receipt of these messages, the receiving network elements wait for a delay time period before sending any additional request messages to the overloaded network element. During the waiting period, the waiting network elements may send request messages to network elements other than the overloaded network element which provide functionality similar to that of the overloaded network element.