Session initiation protocol based advanced intelligent network / intelligent network messaging

A method and system enables distributed transaction oriented telephony functionality for telephony services in a broadband packet network. Exemplary distributed transaction oriented telephony functionality includes Intelligent Network (IN) and Advanced Intelligent Network (AIN) functionality accessed through the legacy Common Channel Signaling (CCS) network using transaction-based messaging protocols, such as Intelligent Network Application Part (INAP) and/or Transaction Capability Application Part (TCAP) protocols. A functional content of a transaction message, such as a TCAP message, is encapsulated in a Protocol Data Unit (PDU) of the broadband packet network. The PDU is forwarded through the broadband packet network to a second network element. The functionality is then invoked using the encapsulated transaction message functional content. In preferred embodiments the PDU is a Session Initiation Protocol (SIP) envelope, into which TCAP message functional content can be mapped.