DICOM PS3.2 2019a - Conformance
F. Association Policies
F. General

The QUERY-RETRIEVE-SCP AE will never initiate Associations; it only accepts Association Requests from external DICOM AEs. The QUERY-RETRIEVE-SCP AE will accept Associations for Verification, C-FIND, and C-MOVE requests. In the case of a C-MOVE request, the QUERY-RETRIEVE-SCP AE will issue a command to the STORAGE-SCU AE to initiate an Association with the Destination DICOM AE to send images as specified by the originator of the C-MOVE Request.

The DICOM standard Application Context Name for DICOM 3.0 is always accepted:

Table F.4.2-10. DICOM Application Context for QUERY-RETRIEVE-SCP AE

Application Context Name


F. Number of Associations

The QUERY-RETRIEVE-SCP AE can support multiple simultaneous Associations. Each time the QUERY-RETRIEVE-SCP AE receives an Association, a child process will be spawned to process the Verification, Query, or Retrieval request. The maximum number of child processes, and thus the maximum number of simultaneous Associations that can be processed, is set by configuration. The default maximum is 10 in total. The maximum number of simultaneous Associations can be either an absolute number or a maximum number for each requesting external Application Entity. The latter flexibility can be useful if communication with one external AE is unreliable and one does not wish 'hung' connections with this AE to prevent Associations with other client AEs.

Table F.4.2-11. Number of Simultaneous Associations as a SCP for QUERY-RETRIEVE-SCP AE

Maximum number of simultaneous Associations

10 (Configurable)

F. Asynchronous Nature

The QUERY-RETRIEVE-SCP AE does not support asynchronous communication (multiple outstanding transactions over a single Association). All Association requests must be completed and acknowledged before a new operation can be initiated.

Table F.4.2-12. Asynchronous Nature as a SCP for QUERY-RETRIEVE-SCP AE

Maximum number of outstanding asynchronous transactions

1 (Not Configurable)

F. Implementation Identifying Information

The implementation information for the Application Entity is:

Table F.4.2-13. DICOM Implementation Class and Version for QUERY-RETRIEVE-SCP AE

Implementation Class UID


Implementation Version Name


Note that the STORAGE-SCU AE, and QUERY-RETRIEVE-SCP AE use the same Implementation Class UID. All EXAMPLE-QUERY-RETRIEVE-SERVER AEs use the same Implementation Version Name. This Version Name is updated with each new release of the product software, as the different AE versions are never released independently.

DICOM PS3.2 2019a - Conformance