In the OSI world, communication partners are represented by application entities. An application entity is an addressable entity in Layer 7 of the OSI Reference Model (Application Layer). Such an application entity is the access point of an FTAM application, for example, via which an OSI-TP communication partner can connect to the FTAM application. In the OSI-TP standard, every application entity is assigned to an application entity title, via which the application entity can be addressed uniquely in the OSI network.
Two forms of AET are defined in the ISO Standard, the Directory Form (transparent form) and the Object Identifier Form (numeric form).
The FTAM functions of openFT (Unix systems) and openFT (Windows) support the Object Identifier Form of the AET. An AET comprises two parts:
Application Process Title (APT)
Application Entity Qualifier (AEQ).
When transmitting with the FTAM protocol, openFT sends a Nil Application Entity Title as a calling or called Application Entity Title by default. This behavior can be modified via operating parameter if desired.
On BS2000 systems, the transfer of Nil AETs can be set system-wide via an optional Rep.
The Nil AET is: 1.3.9999.1.7