WAS v8.5 > WebSphere applications > Messaging resources > Interoperation with WebSphere MQ > Interoperation using a WebSphere MQ link
Messaging between two WebSphere MQ networks through an application server
We can use WebSphere MQ links to send a message from one WebSphere MQ network to another through a WAS application server.
We can exchange messages between two WebSphere MQ networks through an intermediate service integration bus, as shown in the following figure.
Figure 1. Exchanging messages between two WebSphere MQ networks through an intermediate application server.
Configuration and operation of messaging between two WebSphere MQ networks (buses) through an intermediate service integration bus is much simpler if you choose a service integration bus name that complies with WebSphere MQ queue manager naming restrictions:
- The queue managers in the WebSphere MQ networks "see" the intermediate service integration bus as a queue manager, and refer to it by the virtual queue manager name. Provided the service integration bus name complies with WebSphere MQ restrictions for queue manager names, it is possible (and highly desirable) for the virtual queue manager name used by both WebSphere MQ networks to be the same as the bus name used by service integration.
- The service integration bus includes two gateway messaging engines, one connecting to each of the WebSphere MQ networks using WebSphere MQ links (known to the WebSphere MQ gateway queue managers as a WebSphere MQ sender-receiver pair of message channels). The service integration bus must define the two WebSphere MQ networks as foreign buses with names the same as the WebSphere MQ names for the gateway queue managers.
Messages received by the service integration bus from one WebSphere MQ network and destined for another WebSphere MQ network specify both the target queue name and the target queue manager name. Service integration interprets the target queue manager name as a bus name. When the target queue manager is the gateway queue manager for the target WebSphere MQ network, service integration routes the message correctly. When the target queue manager is not the gateway queue manager for the target WebSphere MQ network, there are two options:
- In service integration, define the target queue manager as an indirect foreign bus, connected by the WebSphere MQ foreign bus defined with the name of the gateway queue manager.
- In service integration, define the target queue (destination name or identifier in service integration terminology) and queue manager (bus name in service integration terminology) combination with an alias destination that maps the combination to the target WebSphere MQ network (foreign bus in service integration terminology) with the destination name (identifier) in the form target-queue-name@target-queue-manager-name.
Messages received by the service integration bus from one WebSphere MQ network and destined for another WebSphere MQ network can include a reply-to queue. This is specified as the reply-to queue name and the reply-to queue manager name. When the service integration bus receives the message, the WebSphere MQ link replaces this reply-to information with a service integration bus destination comprising a bus name (which is the WebSphere MQ queue manager name of the gateway queue manager) and a destination name (identifier) of the form reply-to-queue-name@reply-to-queue-manager-name. This new reply-to information travels with the message to the receiving WebSphere MQ application. The combined length of the reply-to queue name, the "@" character, and the reply-to queue manager name must be less than or equal to the WebSphere MQ maximum queue name length of 48 characters.