Interworking SIP and Intelligent Network (IN) Applications

Public Switched Telephone Network (PSTN) services such as 800-number routing (freephone), time-and-day routing, credit-card calling, and virtual private network (mapping a private network number into a public number) are realized by the Intelligent Network (IN). This document addresses means to support existing IN services from Session Initiation Protocol (SIP) endpoints for an IP-host-to-phone call. The call request is originated on a SIP endpoint, but the services to the call are provided by the data and procedures resident in the PSTN/IN. To provide IN services in a transparent manner to SIP endpoints, this document describes the mechanism for interworking SIP and Intelligent Network Application Part (INAP). This memo provides information for the Internet community.