C.5.3 Association Negotiation for C-GET SOP Classes

When an SCP performs the C-GET operation it induces a C-STORE operation for the purpose of transmitting composite SOP Instances for Storage. This induced C-STORE operation (called a sub-operation) requires a switch from the C-GET Presentation Context to a Presentation Context that supports the specific C-STOREsub-operation.

The following negotiation rules apply to retrieval based DICOM Query/Retrieve SOP Classes and Specialized DICOM Query/Retrieve SOP Classes which include the C-GET operation.

The Association-requester (retrieve SCU role) in the A-ASSOCIATE request shall convey:

a) C-GET operation support with:

b) Induced Storage sub-operation support where the SOP Class (in the retrieval SCU role) is acting as a Storage SOP Class in the SCP Role. See Figure C.5-1. For each supported Storage SOP Class, the A-ASSOCIATE request contains:

[pic]

Figure C.5-1 AN EXAMPLE OF THE SUB-OPERATION SCU/SCP ROLES

Note: This negotiation does not place any requirements on the SCU-flag of the SCP/SCU Role Selection Negotiation Sub-Item. It may be set if the Association-requester supports the Storage Service Class in the SCU role.

The Association-acceptor (retrieve SCP role) in the A-ASSOCIATE response shall convey:

a) C-GET operation support with:

b) Induced Storage sub-operation support where the SOP Class (using the retrieval SCP role) is acting as a Storage SOP Class in the SCU Role. See Figure C.5-1. For each supported Storage SOP Class, the A-ASSOCIATE response contains both:

Note: The negotiation does not place any requirements on the SCU-flag of the SCP/SCU Role Selection Negotiation Sub-Item. It may be set if the Association-acceptor accepts the Storage SCP role. Figure C.5-2 illustrates an example of the retrieve (C-GET) negotiation.

Figure C.5-2 illustrates an example of the retrieve (C-GET) negotiation.

C.5.3.1 SOP Class Extended Negotiation

The SOP Class Extended Negotiation allows, at Association establishment, peer DICOM AEs to exchange application Association information defined by specific SOP Classes.

This is achieved by defining the Service-class-application-information field. The Service-class-application-information field is used to define support for relational-retrievals.

[pic] Figure C.5-2 AN EXAMPLE OF THE RETRIEVE (C-GET) NEGOTIATION

Extended negotiation for SOP Classes based on the retrieval services which include C-GET operations is identical to the negotiation defined for C-MOVE which is defined in Section C.5.2.1 of this Annex.

Extended negotiation for the SOP Classes of the Storage Service Class (for the C-STORE sub-operation) is defined in Annex B.