SIP API Developer's Guide

Dialog Termination, Deletion, and Notification

When the stack processes a SIP message, the processing can result in the termination of the dialog. A dialog marked as EARLY terminates if the final response is not in the 200–299 range, or if no response arrives. The termination mechanism for confirmed dialogs are method specific. The BYE method terminates an INVITE dialog and the session that is associated with it. An application can explicitly delete a dialog by using the sip_delete_dialog() function.

When the stack terminates a dialog, it notifies the application if the application has registered a callback function with the stack for this purpose.