5.2.1 DISSEMINATION API

The first scenario assumes the Designated Community wishes to develop applications that can access AIPs using an Application Programming Interface (API) maintained by the OAIS as Access Software. The OAIS may choose to provide this API as an implementation alternative to the production and delivery of a physical DIP for dissemination. This type of service allows the Consumer, as a client, to develop applications that appear to directly access the AIPs. This sort of access could be very useful for applications such as data mining where the creation and shipping of DIPs containing large AICs is impractical. This API could allow an application to virtually navigate through an AIC, deliver the bits of the Content Data Object of selected AIUs to the application and identify locations for obtaining associated Representation Information and PDI. However, as technology evolves, the OAIS moves to new hardware, new media, and new operating systems. If the OAIS wishes to maintain the same API for its Consumers, it will need to provide a ‘wrapper’ around part of its new infrastructure to match its services to the established API. The API will need to be adequately documented and tested to ensure it correctly delivers the AIU Content Information using this new Access Software. This approach should not result in any changes to software developed by the Consumer community. When the API is applicable across a wide range of AIUs in the OAIS or there are a significant number of Consumer applications based on the API, this wrapping approach is clearly feasible and may result in a favorable cost/benefit ratio to the OAIS and its Designated Community. The ‘Layered Model of Information’ presented in annex E of this document further describes some potentially standard APIs.