OSI/TS Configuration and Management Manual
Glossary
OSI/TS Configuration and Management Manual—424831-001
Glossary-2
Application entity.
Application entity.  The part of an application process that interacts with a remote 
application process. In an OSI application itself, the application entity is the part that 
represents the communication functionality necessary for interoperation.
Application entity title.  The name, used with ACSE, that identifies an application entity to 
the OSI network. 
Application Layer.   Layer 7 of the OSI Reference Model. This layer provides the interface 
between user programs (application processes) and the OSI network. Layer 7 includes 
the standards for services such as file transfer, electronic mail, and terminal access.
Application name.  The address by which an application entity is known to the local 
OSI/AS subsystem. Application names are defined locally only. 
APS (application, presentation, and session) procedures.  A set of procedure calls, 
included as part of the OSI/AS subsystem, providing application programs with access 
to the services of ACSE (in the Application Layer), the Presentation Layer, and the 
Session Layer. The names of the APS procedures all begin with the letters APS. APS 
procedures are defined in the EXTDECS files. APS, together with the definitions in the 
ZAPSDDL file, is the API to OSI/AS.
ASE (application service element).  A set of functions to be performed—such as file 
transfer, mail service, or transaction processing—along with all the elements necessary 
to perform that kind of work, to support a particular application.
ASN.1 (Abstract Syntax Notation-1).  A standardized method of representing , encoding, 
transmitting, and decoding data structures. Based on the CCITT X.409 standard, ASN.1 
is the syntax specified for many application protocols, such as ACSE, FTAM, and MMS.  
It is also used by directory services and network management. 
Association.  A connection between Application Layer entities.
Association Control Service Element.   See ACSE (Association Control Service Element).
.
Attach.  An operation performed by an application using OSI/AS or OSI/TS, in the 
Application Layer, Presentation Layer or Session Layer, to indicate that the application 
is willing to receive an incoming connect request or association request from a remote 
application.
Basic concatenation.  A feature of the Session Layer protocol that allows two SPDUs to be 
contained in one TSDU.  This feature is available through the APS procedures, which 
allows applications to invoke a give token primitive or a please token primitive to be 
concatenated with the requested primiti
Called address.   The address to which a connect request is addressed. 
Called user.  The application to which a calling user requests a connection.  For OSI/AS, an 
application calls the APS_ASSOC_ATTACH_ procedure to indicate that it is ready to be 
a called user for a connection.










