10.1.4 N-ACTION SERVICE

The N-ACTION service is used by a DIMSE-service-user to request an action by a peer DIMSE-service-user. It is a confirmed service.

10.1.4.1 N-ACTION parameters

Table 10.1-4 lists the parameters for this service.

Table 10.1-4 N-ACTION PARAMETERS

DIMSE Parameter Name Req/Ind Rsp/Conf
Message ID M
Message ID Being Responded To M
Requested SOP Class UID M
Requested SOP Instance UID M
Action Type ID M C(=)
Action Information U
Affected SOP Class UID U
Affected SOP Instance UID U
Action Reply C
Status M

10.1.4.1.1 Message ID

This parameter identifies the operation. It is used to distinguish this operation from other notifications or operations that the DIMSE-service-provider may have in progress. No two identical values for the Message ID (0000,0110) shall be used for outstanding operations or notifications.

Note: The Message ID (0000,0110) is recommended to be unique within the scope of an Association, to support debug procedures.

10.1.4.1.2 Message ID being responded to

This parameter specifies the Message ID (0000,0110) of the operation request/indication to which this response/confirmation applies.

10.1.4.1.3 Requested SOP class UID

This parameter specifies the SOP Class for which the action is to be performed.

10.1.4.1.4 Requested SOP instance UID

This parameter specifies the SOP Instance on which the action is to be performed.

10.1.4.1.5 Action type ID

This parameter specifies a particular action which is to be performed. It may be included in the success response/confirmation and shall be included if the action reply parameter is included.

Note: Service Class Specifications contained in PS 3.4 defines any application usage of the Action Type ID (0000,1008) parameter.

10.1.4.1.6 Action information

This parameter specifies extra application-specific information when necessary to further define the nature, variations, or operands of the action to be performed. The syntax and semantics of the parameter depend upon the action requested. It may only be included in the request/indication.

Note: Service Class Specifications contained in PS 3.4 defines any application usage of the Action Information parameter.

10.1.4.1.7 Affected SOP class UID

This parameter may be included in the response/confirmation. If included in the response/confirmation, this parameter shall be equal to the Requested SOP Class UID parameter value used in the request/indication.

10.1.4.1.8 Affected SOP instance UID

This parameter specifies the SOP Instance on which the action is to be performed. It may be included in any response/confirmation and when included shall be equal to the Requested SOP Instance UID (0000,1001) parameter value used in the invocation.

10.1.4.1.9 Action reply

This parameter contains the application-specific reply to the action. It may be included in the success response/confirmation.

Note: Service Class Specifications contained in PS 3.4 defines any application usage of the Action Reply parameter.

10.1.4.1.10 Status

This parameter contains the error or success notification for the operation. It shall be included by the performing DIMSE-service-user in any response/confirmation. The following type of status may occur:

⎯ class-instance conflict: the specified SOP Instance is not a member of the specified SOP Class.

⎯ duplicate invocation: the Message ID (0000,0110) specified is allocated to another notification or operation.

⎯ invalid argument value: the action information value specified was out of range or otherwise inappropriate.

⎯ invalid SOP Instance: the SOP Instance UID specified implied a violation of the UID construction rules.

⎯ mistyped argument: one of the parameters supplied has not been agreed for use on the Association between the DIMSE-service-users.

⎯ no such action: the action type specified was not supported.

⎯ no such argument: the action information specified was not supported.

⎯ no such SOP class: the SOP Class was not recognized.

⎯ no such SOP Instance: the SOP Instance was not recognized.

⎯ processing failure: a general failure in processing the operation was encountered.

⎯ resource limitation: the operation was not performed due to resource limitation.

⎯ success: successful operation.

⎯ unrecognized operation: the operation is not one of those agreed between the DIMSE-service-users.

10.1.4.2 N-ACTION service procedures

The following N-ACTION procedures apply:

a) The invoking DIMSE-service-user requests the performing DIMSE-service-user to perform an action on a managed SOP Instance by issuing an N-ACTION request primitive to the DIMSE-service-provider.

b) The DIMSE-service provider issues an N-ACTION indication primitive to the performing DIMSE-service-user.

c) If the operation can be performed, the performing DIMSE-service-user applies the action to the specified SOP Instance and generates a response indicating acceptance of the N-ACTION request primitive by issuing an N-ACTION response primitive to the DIMSE-service-provider. In this case the following procedure does not apply. The Action Reply may be included in a successful response.

d) If the operation cannot be performed, then the performing DIMSE-service-user rejects the N-ACTION request by issuing an N-ACTION response primitive with the appropriate error code to the DIMSE-service-provider.

e) The DIMSE-service-provider issues an N-ACTION confirmation primitive to the invoking DIMSE-service-user, completing the N-ACTION operation.

The performing DIMSE-service-user may return an N-ACTION response primitive with the status of Failed or Refused before the entire N-ACTION indication (Data Set) has been completely transmitted by the invoking DIMSE-service-user. A N-ACTION response primitive with the status of Success or Warning shall not be returned until the entire N-ACTION indication has been received by the performing DIMSE-service-user.

Note: Such an occurrence of a "Failed" response is often called an early failed response.