About the OSA Address Table (OAT)

About the chapter

If you are installing any OSA feature other than CHPID type OSD and you are not using the OSA/SF GUI, this chapter provides useful information.

If either of the following cases apply, you don't need to know the details in this chapter, but you might want to use the information for reference:
  • If you are installing OSA-Express features to run only as a CHPID type OSD (QDIO mode), the correct OAT entries are automatically created from I/O hardware configuration data and Communications Server.
  • If you are using the OSA/SF GUI to customize any OSA feature other than CHPID type OSD, configuration windows organize the OAT and provide an easy method for creating and changing entries.

The OSA Address Table (OAT) is used to define which devices the OSA uses to transfer data and commands to/from each attached host. For QDIO CHPIDs, the OAT is automatically configured using the TCPIP profiles and IOCDS definitions. For non-QDIO features, the OAT is defined manually by the user and transferred to the OSA when the OSA/SF REXX or GUI interface configures the CHPID. The hardware configuration (IOCDS) has input to the OAT and must be defined before an OSA can transfer data. See OSA-Express hardware configuration for more information.

There are two methods available for manually creating an OAT using REXX:
  • The Get OAT Command
  • Sample Templates in IOA.SIOASAMP (z/OS) and on the E (200) minidisk (z/VM)

There are advantages to both methods. If you already have a configuration on the OSA and you want to make a change, use the Get OAT command. If you are creating an OAT for the first time, the templates are easier to use.

Instructions for changing the templates are included in the legend appended to the Get OAT output or the templates.

For the GUI, panels allow the user to configure the devices needed or the Get Configuration command can be used to "prefill" the data with what is currently configured on the OSA

The OAT contains the following information:
  • Image number in the format of css.image where css is a one-digit channel subsystem identifier and image is a one-digit hex image number
  • Device number(s) of all valid devices
  • Type of connection....Passthru, SNA, QDIO
  • Connection dependant information such as port number, IP address, default route indication, etc.
  • Status, such as Started or Started and In Use
  • Indication if the entry is known only by OSA, known only by the IOCDS, or both (which indicates data can flow on this path)
Parent topic: OSA-Express reference