The DICOM Verification service
The DICOM Verification service is probably the simplest DICOM service. It is used to verify DICOM connectivity between two DICOM nodes. Basically, it is the DICOM-equivalent of the “ping” network command, and indeed it is often referred to as DICOM ping.
The DICOM Verification service follows the usual SCP / SCU pattern: a DICOM Verification SCP acts as a server and waits for incoming connections by DICOM Verification SCUs. In turn, a DICOM Verification SCU, in order to verify the DICOM connectivity with another node acting as a DICOM Verification SCP, actively connects to that SCP node, sends the verification request, and waits for the verification response by the SCP.
From the protocol point of view, the DICOM Verification service is implemented through the C-ECHO message: the SCU sends a C-ECHO-RQ (request) message to the SCP, and the SCP is expected to answer returning a C-ECHO-RSP (response) message to the SCU.
The DICOM Verification service is often used during the initial configuration phase of new DICOM nodes, in order to ensure correct communication with the other nodes of the DICOM network.