SPD OptiConnect

 

System product division (SPD) is a bus architecture that allows I/O to communicate to the processor. SPD OptiConnect is a high-speed physical OptiConnect connection that uses the SPD bus technology.

SPD OptiConnect can refer to the OptiConnect feature that provides high-speed system-to-system connectivity through the SPD bus technology. SPD OptiConnect requires an SPD bus that is available on earlier System i™ models and through the 5077 SPD migration unit supported on some iSeries™ 8xx models. Models with HSL-2 ports do not support SPD OptiConnect.

The systems in an SPD OptiConnect network share a common external optical system bus that is located in a dedicated expansion unit or frame (also called an SPD OptiConnect hub unit). The system that provides this system bus is called the hub system. The hardware used to create the hub system for an SPD OptiConnect network consists of a dedicated system I/O expansion unit or frame. Each system that plugs into this bus with an OptiConnect receiver card is called a satellite system. Each satellite system dedicates one of its external system buses to connect to the receiver card in the hub system's expansion unit or frame.

Redundancy is supported in SPD OptiConnect networks through SPD bus redundancy. Redundancy requires a second SPD OptiConnect hub, an extra set of OptiConnect receiver cards, and an extra I/O expansion unit or frame, along with another set of cables.

Systems attached to the hub system do not use the hub system's CPU resources.

Figure 1. SPD OptiConnect

Figure 1 shows a dual bus configuration, providing full redundancy in the SPD OptiConnect system area network. If one of the hub systems fails, the SPD OptiConnect network remains in service and all communications activity is run through the other hub. When both hubs are operating, the communications traffic is shared between both. This increases the bandwidth with two paths available for use.

An SPD OptiConnect network can consist of up to 14 systems (one hub and 13 satellites) with full system-to-system connectivity. A satellite system can communicate with both hub systems and all the other satellite systems on the same shared bus. Interoperability between operating system versions is maintained so that systems at different release levels can be connected in the same SPD OptiConnect network. With additional hubs, up to 32 systems can be supported.

iSeries 840, 830, and 270 can participate in an SPD OptiConnect network by using a migration unit.

 

Parent topic:

OptiConnect hardware

Related reference
High Availability and Clusters