In the communication, the server service in accordance with regulations, followed by the query queue, then complete a visit to all queues returned to the queue 1.
During communication, the server queries the queue in turn according to the service procedure, and returns to queue 1 after completing one visit to all queues.
In the communication process, the server queries the queues in turn according to the service rules, and returns to queue 1 after one visit to all queues.<br>