SIP API Developer's Guide

UAS Dialog Creation

When the stack receives a dialog creating request, it creates a partial dialog by using the request. The stack sends the partial dialog to the application along with the request. The stack completes the dialog when the application sends a response. Because the stack does not insert the partial dialog into a hash table, the stack does not return partial dialogs as results of a lookup. The stack starts a timer when it creates the partial dialog. The timer's duration is set to the duration of an INVITE transaction timeout. If the UAS does not respond during this time interval, the stack deletes the partial dialog. If the application registers a callback function with the stack for dialog deletion notifications, the stack invokes the callback function before deleting the partial dialog. The stack also deletes the partial dialog if the response is outside the 100–299 range.