How raw reason code changes and utilization event logging is handled

Whenever a raw reason code change occurs, a new utilization event is logged in the database. All utilization event logging uses Without Response mode and Microsoft Message Queuing (MSMQ) so that the utilization events are properly resolved and recorded.

In Without Response mode, the UCO does not receive the notifications about the delivery status of messages for its calls. The MES middleware pulls the event logs from the queue and records them in the MES database. If the middleware detects that more than one event occurred within the same 1‑second time slice, the most recent utilization event is logged and the other events that occurred in that 1-second time slice are overwritten. No errors are logged as this is standard behavior of MES. If other errors are encountered while logging an event, such as the entity can no longer capture utilization data or the raw reason code is no longer associated to the entity, then the middleware will log a rejected message to the MES database. These errors will be read by the UCO later and shown in the Rejected Messages attributes.

To allow a UCO to log messages in the Message Queue while in Without Response mode, an Anonymous Logon user with the Send Message privilege must be added to the MESAsyncQueue on the middleware server. Otherwise, the messages will not be logged. See Add an anonymous logon user to MESAsyncQueue.