From the NetBeans IDE Projects window, right-click the Service Assembly node under your composite application, and select Edit from the popup menu.
The CASA Editor opens containing your composite application.
In the CASA Editor, click the QOS icon located on the link between your JBI Module and the WSDL port you want to configure.
The QOS Properties Editor appears.
In the QOS Properties Editor, click the property field for maximumConcurrencyLimit under ThrottlingExtension, and enter an integer for the maximum number of concurrent messages allowed for this endpoint.
Click Close.
The appropriate throttling configuration for the connection is generated in the project's jbi.xml file, when the service assembly is built.