OSI/FTAM Programming Guide

ISO FTAM Concepts
HP NonStop OSI/FTAM Programming Guide—528612-001
2-21
Negotiation of Service Class and Functional Units
For the groupings specified in the file-management service class, the value of the
threshold parameter must be equal to the number of primitives in the group,
excluding F-BEGIN-GROUP and F-END-GROUP. For information about the
threshold parameter, refer to Grouping Control on page 4-15.
File-Transfer-and-Management Service Class
The file-transfer-and-management service class constrains the services to include only
those sequences of services allowable in either the file-transfer service class or the
file-management service class and described in the subsections above.
For the groupings specified in the file-transfer-and-management service class, the
value of the threshold parameter must be equal to the number of primitives in the
group, excluding F-BEGIN-GROUP and F-END-GROUP. For information about the
threshold parameter, refer to Grouping Control on page 4-15.
Negotiation of Service Class and Functional Units
The initiator and responder negotiate service classes and functional units when they
establish an association. The negotiation proceeds as follows:
1. The initiator proposes a list of acceptable service classes on the F-INITIALIZE
request primitive. Acceptable service class lists include the following:
•
File-transfer, unconstrained
•
File-management, unconstrained
•
File-access, unconstrained
•
File-transfer, file-access, unconstrained
•
File-transfer, file-management, file-transfer-and-management, unconstrained
The unconstrained service class is possible with each of the service-class
combinations shown above. Note that NonStop FTAM does not support the
unconstrained service class.
In the same primitive, the initiator also proposes a list of the functional units that
the initiator supports and wishes to use during the association. This list must
include all functional units mandatory for the service classes proposed. The kernel
functional unit is not included in the list because it is always mandatory.
2. The responder selects the highest service class that it supports from the proposed
list of service classes. The order of the service classes, from highest to lowest is:
•
File-access service class
•
File-transfer-and-management service class
•
File-transfer service class
•
File-management service class