If you want to control which users can subscribe to or publish particular topics, you need a User Name Server. Brokers performing publish/subscribe can run on many platforms, but use a common User Name Server. This User Name Server can run on any supported platform. However, you must ensure that user IDs associated with requests coming from distributed platforms for deploys or publish/subscribe are defined on those distributed platforms as upper case.
The following steps show you how to create and customize a z/OS User Name Server. See z/OS customization overview for a general overview of the customization process.
Much of the customization is done in OMVS, so you need to be familiar with this environment. Sample definitions are used in the examples: MQP1 is a queue manager and MQP1UNS a User Name Server.