MQSeries uses these definitions to determine how to route messages across a complex network. Similarly, applications can send messages to aliased names in a local queue definition, rather than the named remote destination queue or its queue manager. For their part, application programmers should specify logical queue names rather than destination queue manager names. Using logical names lets MQSeries access the information network managers insert into the remote queue definitions. The physical arrangement of queues then remains in the purview of the network manager, where it belongs.
Aliases have another benefit because of their logical rather than physical nature.
A network manager can configure multiple channels, each with a different route to a destination and different class of service, and equate aliases to each path. The application designer is then free to select an appropriate alias, depending on the class of service each part of the business logic needs. Unfortunately, the application programmer must be aware of the network manager's use of reply-to queue definitions because the name the application uses here differs from the actual queue where MQSeries stores the message. MSMQ site gates accomplish for MSMQ what transmission queues do for MQSeries. Each message requiring transport to a different LAN traverses a site gate, which a network administrator configures for message routing.