Материал: part02

Attribute Name: Attributes supported for returned C-FIND Responses.​

Tag: Appropriate DICOM tag for this attribute.​

VR: Appropriate DICOM VR for this attribute.​

Types of Matching: The types of Matching supported by the C-FIND SCP. A "S" indicates the identifier attribute can specify Single​ Value Matching, a "R" will indicate Range Matching, a "*" will denote wild card matching, an 'U' will indicate universal matching, and​ 'L' will indicate that UID lists are supported for matching. "NONE" indicates that no matching is supported, but that values for this​ Element in the database can be returned.​

Table F.4.2-19. QUERY-RETRIEVE-SCP AE C-FIND Response Status Return Behavior​

- Standard -​

F.4.2.2.4.1.4 SOP Specific Conformance for Retrieval SOP Classes​

The QUERY-RETRIEVE-SCP AE will convey to the STORAGE-SCU AE that an Association with a DICOM Application Entity named​ by the external C-MOVE SCU (through a MOVE Destination AE Title) should be established. It will also convey to the STORAGE-​ SCU AE to perform C-STORE operations on specific images requested by the external C-MOVE SCU. One or more of the Image​ Storage Presentation Contexts listed in Table F.4.2-6 will be negotiated.​

The QUERY-RETRIEVE-SCP AE can support lists of UIDs in the C-MOVE Request at the Study, Series, and Image Levels. The list​ of UIDs must be at the Level of the C-MOVE Request however. For example, if the C-MOVE Request is for Series Level retrieval but​ theidentifiercontainsalistofStudyUIDsthentheC-MOVERequestwillberejected,andtheA900FailedStatusCodewillbereturned​ in the C-MOVE Response.​

AninitialC-MOVEResponseisalwayssentafterconfirmingthattheC-MOVERequestitselfcanbeprocessed.Afterthis,theQUERY-​ RETRIEVE-SCP AE will return a response to the C-MOVE SCU after the STORAGE-SCU AE has attempted to send each image.​ This response reports the number of remaining SOP Instances to transfer, and the number transferred having a successful, failed,​ or warning status. If the Composite SOP Instances must be retrieved from long-term archive prior to export there may be quite a long​ delay between the first C-MOVE Response and the next one after the attempt to export the first image. The maximum length of time​ for this delay will depend on the particular type of archive used but typically varies between 3 and 10 minutes.​

Table F.4.2-20. QUERY-RETRIEVE-SCP AE C-MOVE Response Status Return Behavior​

- Standard -​

Note that the Warning Status, B000 (Sub-operations complete - One or more Failures) is never returned. If a failure occurs during​ export to the C-MOVE Destination AE by the STORAGE-SCU AE then the entire task is aborted. Thus any remaining matches are​ not exported.​

Table F.4.2-21. QUERY-RETRIEVE-SCP AE Communication Failure Behavior​

TimeoutexpiryforanexpectedDICOMMessageRequest​The Association is aborted by issuing a DICOM A-ABORT.​

(DIMSEleveltimeout).I.e.TheQUERY-RETRIEVE-SCP​

AE is waiting for the next C-FIND or C-MOVE Request​Error message is output to the Service Log. If the STORAGE-SCU AE is​ on an open Association but the timer expires.​ still exporting Composite SOP Instances as a result of an earlier C-MOVE​ RequestreceivedonthisAssociation,itwillcontinueattemptingtocomplete​

the entire C-MOVE Request.​

Timeout expiry for an expected DICOM PDU or TCP/IP​The Association is aborted by issuing a DICOM A-ABORT.​ packet (Low-level timeout). I.e. The​

QUERY-RETRIEVE-SCP AE is waiting for the next​ message PDU but the timer expires.​

Association aborted by the SCU or the network layers​ Error message is output to the Service Log. If the STORAGE-SCU AE is​ indicatecommunicationloss(i.e.,low-levelTCP/IPsocket​still exporting Composite SOP Instances as a result of an earlier C-MOVE​ closure)​ RequestreceivedonthisAssociation,itwillcontinueattemptingtocomplete​

the entire C-MOVE Request.​

- Standard -​

F.4.2.3 STORAGE-SCP Application Entity Specification​

F.4.2.3.1 SOP Classes​

The STORAGE-SCP AE provides Standard Conformance to the following DICOM SOP Classes:​

Table F.4.2-22. SOP Classes for STORAGE-SCP AE​

These are the default SOP Classes supported. By altering the configuration it is possible to support additional or fewer SOP Classes.​

F.4.2.3.2 Association Policies​

F.4.2.3.2.1 General​

TheSTORAGE-SCPAEcanbothacceptandproposeAssociationRequests.TheSTORAGE-SCPAEwillacceptAssociationRequests​ for the Verification, Storage, and Storage Commitment Push Model Services. It will propose Associations only for the Storage Com-​ mitment Push Model Service.​

The DICOM standard Application Context Name for DICOM is always accepted and proposed:​

Table F.4.2-23. DICOM Application Context for STORAGE-SCP AE​

The STORAGE-SCP AE can support multiple simultaneous Associations requested by peer AEs. Each time the STORAGE-SCP AE​ receives an Association, a child process will be spawned to process the Verification, Storage, or Storage Commitment Push Model​ Service requests. The maximum number of child processes, and thus the maximum number of simultaneous Associations that can​ beprocessed,issetbyconfiguration.Thedefaultmaximumnumberis10intotal.ThismaximumnumberofsimultaneousAssociations​ can be either an absolute number or a maximum number for each requesting external Application Entity. The latter flexibility can be​ usefulifcommunicationwithoneexternalAEisunreliableandonedoesnotwish'hung'connectionswiththisAEtopreventAssociations​ with other client AEs.​

The STORAGE-SCP AE initiates one Association at a time for sending Storage Commitment Push Model N-EVENT-REPORTs to​ peer AEs.​

Table F.4.2-24. Number of Simultaneous Associations as an SCP for STORAGE-SCP AE​

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F.4.2.3.2.3 Asynchronous Nature​

TheSTORAGE-SCPAEdoesnotsupportasynchronouscommunication(multipleoutstandingtransactionsoverasingleAssociation).​ The STORAGE-SCP AE does permit an SCU to send multiple Storage Commitment Push Model Requests before it has sent back​ any N-EVENT-REPORT Notifications. However, the STORAGE-SCP AE must send an N-ACTION Response before permitting an-​ other N-ACTION Request to be received so the DICOM communication itself is not truly asynchronous.​

Table F.4.2-25. Asynchronous Nature as a SCP for STORAGE-SCP AE​

There is no limit on the number of outstanding Storage Commitment Push Model Requests that can be received and acknowledged​ before the STORAGE-SCP AE has responded with the corresponding N-EVENT-REPORT Notifications.​

Table F.4.2-26. Outstanding Storage Commitment Push Model Requests for STORAGE-SCP AE​

Maximum number of outstanding Storage Commitment Requests for which no N-EVENT​ No Maximum Limit​ Notification has been sent​

F.4.2.3.2.4 Implementation Identifying Information​

The implementation information for this Application Entity is:​

Table F.4.2-27. DICOM Implementation Class and Version for STORAGE-SCP AE​

Note that the STORAGE-SCP AE specifies a different Implementation Class UID than that used by the other Application Entities. All​ EXAMPLE-QUERY-RETRIEVE-SERVERAEsusethesameImplementationVersionName.ThisVersionNameisupdatedwitheach​ new release of the product software, as the different AE versions are never released independently.​

F.4.2.3.3 Association Initiation Policy​

F.4.2.3.3.1 Activity - Send Storage Commitment Notification Over New Association​

F.4.2.3.3.1.1 Description and Sequencing of Activity​

TheSTORAGE-SCPAEwillinitiateanewAssociationifaStorageCommitmentPushModelNotification(N-EVENT-REPORT)cannot​ be sent back over the original Association used to send the corresponding request. A new Association will always be requested by​ the STORAGE-SCP AE in such cases even if the peer AE requests another Association after the original has been closed (i.e., A​ peer AE opens an Association and sends some Storage requests and a Storage Commitment Push Model request. Before the​ STORAGE-SCP AE can send the Storage Commitment Push Model N-EVEN-REPORT the Association is closed. The peer AE then​ opens another Association and begins to send Storage requests. In such a case the STORAGE-SCP AE will always initiate a new​ Association to send the N-EVENT-REPORT even though it could send the N-EVENT-REPORT over the new Association opened by​ the peer AE).​

AnAssociationRequestissenttothepeerAEthatsenttheStorageCommitmentPushModelrequestanduponsuccessfulnegotiation​ oftherequiredPresentationContexttheoutstandingN-EVENT-REPORTissent.IftherearemultipleoutstandingN-EVENT-REPORTs​ tobesenttoasinglepeerAEthentheSTORAGE-SCPAEwillattempttosendthemalloverasingleAssociationratherthanrequesting​ a new Association for each one. The Association will be released when all the N-EVENT-REPORTs for the peer AE have been sent.​ If any type of error occurs during transmission (either a communication failure or indicated by a Status Code returned by the peer AE)​ over an open Association then the transfer of N-EVENT-REPORTs is halted. A new Association will be opened to retry sending out-​ standingN-EVENT-REPORTs.Themaximum numberoftimestheSTORAGE-SCP AE willattempttoresendanN-EVENT-REPORT​ is configurable, along with the amount of time to wait between attempts to resend.​

If the STORAGE-SCP AE sends a Notification request (N-EVENT-REPORT-RQ) over the original Association opened by the peer​ AE but receives a request to close the Association rather than a response to the Notification (N-EVENT-REPORT-RSP) then this is​ handled in the same way as if the request to close the Association had been received before trying to send the Notification request.​ Thus, the STORAGE-SCP AE will then open a new Association to resend the Notification request.​

- Standard -​