...
Note that the SHR will NOT participate in the Patient Identity Feed transactions (ITI-8, ITI-44) when performing transactions in the Document Registry role. In the wider OpenHIE architecture, the Interoperability Layer performs the task of resolving patient identifiers from the Client Registry (acting as Patient Identity Source) before sending transactions to the Shared Health Record. In addition, the SHR will also not provide the ITI-42 Register Document Set.b transaction functionality, which will be provided by the IOL whenever a Provide and Register Document Set.b transaction is received. It is therefore the combination of the SHR (both OpenMRS and HIEOS) and the IOL that provides a complete implementation of an XDS Registry and Repository.
The SHR (with the IOL) plays a dual role of both Document Registry and Document Repository. As a registry the SHR can store metadata about documents, while as a repository, the SHR can provide the storage for these documents. The SHR must switch between roles depending on the transaction, and should, if required, be able to perform just the role of registry (or repository) for an external 3rd party repository (or registry).
...