A DICOM Application Entity Title uniquely identifies a service or application on a specific system in the network. Application Entity Titles are independent of network topology so a device may be physically moved while its corresponding Application Entity Title may remain the same. See PS 3.5 for the encoding of DICOM Application Entity Titles.
Note: DICOM Application Entity Title was called Logical Address in the ACR-NEMA Standard.
DICOM Application Entity Titles are used in three instances of communication:
a) to identify the Called/Calling Application Entities. They are used to establish an association and to ensure that the association is established with the expected application.
b) to identify the originator and intended destination of DICOM Retrieve Services (see PS 3.4). They are conveyed in DICOM Commands with messages of the DIMSE C-MOVE and C-STORE Services exchanged over an established association.
c) to identify the location of a Retrieve Service SCP for one or more SOP Instances. They are conveyed in DICOM DataSets of various services.
DICOM Application Entity Titles are used in the Called/Calling Application Entity Title fields of the Upper Layer Service, in the Move Destination and Move Originator Application Entity Title data elements in the DICOM Message Command Set, and in various Attributes of the DICOM Message Data Set.
Notes: 1. A single Application Entity Title can be associated with multiple network addresses assigned to a single system (e.g., multi-homed host).
2. A single Application Entity Title can be associated with multiple TCP Ports using the same or different IP Addresses.
3. A single network access point (IP Address and TCP Port) can support multiple Application Entity Titles.
A DICOM system on a network may support several application processes identified by different DICOM Application Entity Titles.
Upon receiving an association request, the Called Application Entity Title shall be validated so an association can be rejected when the corresponding local application does not exist.