C-ECHO (DICOM Verification)
C-ECHO is the DICOM network service that tests whether two devices can communicate, without transferring any image data — the equivalent of a ping at the DICOM layer.
What C-ECHO (DICOM Verification) means in practice
It confirms considerably more than a network ping: a successful C-ECHO means the association was negotiated and the remote device accepted the calling AE Title, so the addressing, the port and the AE Title configuration are all correct. Most modality consoles expose it as a "verify" or "test" button next to the destination settings, and it is the first thing to try when a send fails.
Source
This definition follows NEMA PS3.7 §9.1.5 (C-ECHO), Verification Service Class in PS3.4 Annex A, published by NEMA as part of the DICOM standard.
Related terms
AE Title
An AE Title is the name a DICOM device identifies itself by on the network, used together with its IP address and port to address it when another device opens an association.
C-STORE
C-STORE is the DICOM network service used to transfer a composite object — an image or similar instance — from one device to another, and it is the operation behind "sending a study" to a PACS.
Storage SCP
A Storage SCP is the role a device plays when it accepts incoming DICOM images, listening for C-STORE requests and storing what it receives — the role a PACS or an archiving viewer performs.
Related on this site: Verifying a console connection.