2.2.3 System control 46  IBM z14 (3906) Technical Guide The various system elements are managed through the FSPs. An FSP is based on the  IBM PowerPCfi microprocessor technology. Each FSP card has two ports to connect to two  internal Ethernet LANs, through system control hubs (SCH1 and SCH2). The FSPs  communicate with the SEs and provide a subsystem interface (SSI) for controlling  components.  Figure 2-11 shows a conceptual overview of the system control design. Note:  The maximum configuration has four CPC drawers and five PCIe or I/O drawers for  z14. The various supported FSP connections are referenced in Figure 2-11. Figure 2-11 Conceptual overview of system control elements A typical FSP operation is to control a power supply. An SE sends a command to the FSP to  start the power supply. The FSP (by using SSI connections) cycles the various components of  the power supply, monitors the success of each step and the resulting voltages, and reports  this status to the SE. Most system elements are duplexed ( n +1), and each element has at least one FSP. Two  internal Ethernet LANs and two SEs, for redundancy, and crossover capability between the  LANs, are available so that both SEs can operate on both LANs. The Hardware Management Consoles (HMCs) and SEs are connected directly to one or two  Ethernet Customer LANs. One or more HMCs can be used.