http://www.rfc-editor.org/rfc/rfc7200.txt
RFC 7200: A Session Initiation Protocol (SIP) Load-Control Event Package, C. Shen, H. Schulzrinne, A. Koike2014-04-01T23:00:00-00:00This specification defines a load-control event package for the Session Initiation Protocol (SIP). It allows SIP entities to distribute load-filtering policies to other SIP entities in the network. The load-filtering policies contain rules to throttle calls from a specific user or based on their source or destination domain, telephone number prefix. The mechanism helps to prevent signaling overload and complements feedback-based SIP overload control efforts.