When it has been enabled, this notification makes it possible for an APPN topology application to get asynchronous notifications of DLUR-DLUS session changes, and thus to reduce the frequency with which it polls for these changes. This notification is sent whenever there is a dlurDlusSessnStatus object transition to 'inactive' or 'active' state in the dlurDlusTable. This notification is only sent for row creation if the row is created with a value of 'active' for dlurDlusSessnStatus. This notification is only sent for row deletion if the last value of dlurDlusSessnStatus was 'active'. In this case, the value of dlurDlusSessnStatus in the notification shall be 'inactive', since the deletion of a row indicates that the session is no longer active. The notification is more than a simple 'poll me now' indication. It carries both a count of DLUR-DLUS table changes, and the session status itself. The count of changes allows an application to detect lost notifications, either when polling or upon receiving a subsequent notification, at which point it knows it must retrieve the entire dlurDlusTable again. Generation of this notification is controlled by the appnTrapControl object.