IETF RFC 7200 PDF

This 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.