The DICOM Storage service
The DICOM Storage service is used to transfer DICOM images and other related digital data from a DICOM node to another DICOM node. It is a fundamental service in DICOM, as it allows exchange of data among multiple devices over the DICOM network.
The DICOM Storage service follows the usual SCP / SCU pattern: a DICOM Storage SCP acts as a server and waits for incoming connections by DICOM Storage SCUs. In turn, a DICOM Storage SCU, in order to send DICOM images (or other related data) to another node acting as a DICOM Storage SCP, actively connects to that SCP node, sends the storage request accompanied with the actual data to transfer, and waits for the storage response by the SCP.
From the protocol point of view, the DICOM Storage service is implemented through the C-STORE message: the SCU sends a C-STORE-RQ (request) message to the SCP, also including the actual dataset to transfer, and the SCP is expected to answer returning a C-STORE-RSP (response) message to the SCU, communicating success or failure of the storage request.