Each time a user submits a request (command or file-to-file transaction) to BDT, the request travels from the user address space to the TQI address space to the BDT address space on the global (scheduling) node. From there, BDT writes the request onto the BDT work queue. For example, if a user submits a request through a TSO terminal, the request travels from the TSO address space to the TQI address space to the BDT address space. The user and TQI address spaces may be in the same processor as the BDT address space or in different processors within the same JES complex. Thus, the request has to travel from one address space to another and possibly from one processor to another. The actual path that a request follows depends on the configuration of your installation and whether your node is the global (scheduling) node.