On the one hand, there is the enterprise platform with JMS for asynchronous messages and EJB Timers.
一方面，企业平台有用于异步消息的JMS和EJB定时器。
Message Façade receives asynchronous messages from the PBX/ACD (private branch exchange/automated call distributor).
Message Façade 从 PBX/ACD（专用交换机/自动呼叫分配器）接收异步消息。
The example messages in Figure 5 show synchronous messages; however, in sequence diagrams you can model asynchronous messages, too.
图 5 中的消息实例显示同步消息；然而，在序列图中，你也能为异步消息建模。
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