String dialogId = sipRequest.getDialogId(true);
dialog = sipStack.getDialog(dialogId);
if (dialog == null) {
dialog = sipStack.createDialog((SIPTransaction) transaction);
// create and register the dialog and add the inital route set.
dialog.addTransaction(sipTransaction);
dialog.addRoute(sipRequest);
sipTransaction.setDialog(dialog, null);
} else {
sipTransaction.setDialog(dialog, sipRequest.getDialogId(true));