Discovering Services a CA Provides

Step One: Discover Occupied IO Controller Slots in IOU

Assuming that the CA just discovered is a TCA within an IOU, software can then issue a DevMgtGet(IOUnitInfo) GMP (Device Management read of the IOUnitInfo attribute) to discover the number of slots that exists in the IOU and which ones are currently occupied by IOCs.

Step Two: Obtain Number of Services IOC Supports

This is accomplished by reading the IOControllerProfile.ServiceEntries attribute for each of the IOCs that are present.

Step Three: Obtain List of Services Supported by Each IOC

This is accomplished by reading the ServiceEntries attribute for each of the IOCs that are present. This attribute consists of a list of all the services provided by the respective IOC. Each entry contains:

• The ServiceName. This the 40-byte text name of the service.

• The ServiceID. This is the 64-bit ID of that service.

Step Four: ServiceID Provided in Connection Request

As will be seen later in this chapter, the ServiceID of the service to establish a communications channel with is supplied to the remote CA during the connection establishment process.