BS ISO/IEC 9040:1997

1 Scope
2 Normative references
3 Definitions
    3.1 Global OSI definitions
    3.2 Association Control Service Element definitions
    3.3 Virtual Terminal Service definitions
4 Abbreviations
    4.1 General
    4.2 Modes of operation
    4.3 VTE model components
    4.4 Access-rules
5 Conventions
6 General features
    6.1 Introduction
    6.2 Features of the Virtual Terminal Basic Class
          Service
    6.3 VT Environment(VTE) and VTE-parameters
    6.4 Virtual Terminal Environment Profiles
    6.5 Dialogue Control
7 Communication facilities
    7.1 Establishment facility
    7.2 Termination facility
    7.3 Negotiation facility
    7.4 Data Transfer facility
    7.5 Delivery Control facility
    7.6 Dialogue Management facility
    7.7 Interrupt facilities
    7.8 Exception Reporting facility
8 Modes of operation
    8.1 S-mode
    8.2 A-mode
9 Access-rules
10 VT functional units
    10.1 Negotiation functional units
    10.2 Negotiated release functional unit
    10.3 Urgent Data functional unit
    10.4 Break functional unit
    10.5 Enhanced Access-rules functional unit
    10.6 Structured Control Objects functional unit
    10.7 Blocks functional unit
    10.8 Fields functional unit
    10.9 Reference Information Objects functional unit
    10.10 Ripple functional unit
    10.11 Exceptions functional unit
    10.12 Context Retention functional unit
11 VT Environment profiles (VTE-profiles)
12 The VTE Model
13 Display Objects
    13.1 Structure
    13.2 Attributes
14 Control objects
    14.1 CO structure facilities and related restrictors
    14.2 Standard control object for dynamic termination
          conditions
    14.4 Standard control object for notifying termination
    14.5 Standard control object for echo control
    14.6 Standard control object for ripple mode
          editing
15 Reference Information Objects
    15.1 Structure
    15.2 Generation and use of RIOs
16 Device objects
17 VTE Parameters and directed graph
    17.1 Directed graph of VTE-parameters
    17.2 VTE consistency rules
18 Display Object VTE-parameters
    18.1 Primary VTE-parameters
    18.2 Secondary VTE-parameters
    18.3 Tertiary VTE-parameter
19 Operations on display objects
    19.1 Addressing operations
    19.2 Ripple operations
    19.3 Logical ripple operations
    19.4 Update operations
    19.5 Access control over display object
20 Control object VTE-parameters
    20.1 Usage and effects of control object VTE-parameters
    20.2 Usage and effects of data element VTE-parameters
    20.3 Standard control objects
21 Reference Information Object VTE-parameters
    21.1 Availability
    21.2 VTE-parameters for RIOs
22 Operations on RIOs
    22.1 Availability
    22.2 Identification of RIO and RIO records
    22.3 RIO update operations
    22.4 RIO reference operations
23 Device object VTE-parameters
    24.1 No delivery-control
    24.2 Simple delivery-control
    24.3 Quarantine delivery-control
    24.4 Implicit delivery
    24.5 Update queues and priority handling
25 Communication Model
26 VT Services
27 VT service sequences
    27.1 Phases
    27.2 Phase transitions
    27.3 Ownership of the WAVAR access-right
    27.4 Availability and usage conditions of VT services
    27.5 Service collisions in A-mode
28 Establishment facility
    28.1 VT-ASSOCIATE service
29 Termination facility
    29.1 Services
    29.2 VT-RELEASE service
    29.3 VT-U-ABORT service
    29.4 VT-P-ABORT service
30 Negotiation facilities
    30.1 Switch Profile negotiation
    30.2 Multiple interaction negotiation
    30.3 Sequence control for multiple interaction
          negotiation
31 Data Transfer facility
    321.1 VT-DATA service
32 Delivery Control facility
    32.1 VT-DELIVER service
    32.2 VT_ACK RECEIPT service
33 Dialogue management facility
    33.1 VT-GIVE-TOKENS service
    33.2 VT-REQUEST-TOKENS service
34 Destructive Interrupt facility
    34.1 VT-BREAK service
35 Exception reporting facility
    35.1 VT-P-EXCEPTION service
Annex A Default VTE-profiles
    A.1 Introduction to VTE-profile definitions
    A.2 Notation for definition of VTE-profiles
    A.3 S-mode Default VTE-profile, vt-b-spr-sd
    A.4 A-mode Default VTE-profile, vt-b-spr-ad
Annex B Explanatory notes
    B.1 Types of VT communication supported
    B.2 Aid to understanding the role of display objects
    B.3 Relation of update-window to buffering
    B.4 Control object semantics
    B.5 Echoing
    B.6 Echo control
    B.7 Echo control algorithm
    B.8 Termination conditions
    B.9 Synchronisation of update delivery
    B.10 Multiple Interaction Negotiation
    B.11 Semantics of display objects
    B.12 Repertoires
    B.13 Use of ISO 6429 Additional Controls in repertoires
    B.14 Font Assignment VTE-parameters
    B.15 Net-effecting
    B.16 Interrupt facilities
    B.17 Emphasis attribute
    B.18 Supplementary explanatory material on field
          facilities
    B.19 Supplementary explanatory material on block
          facilities
Annex C ASN.1 OBJECT IDENTIFIER values
    C.1 For identification of this International Standard
    C.2 For identification of attribute assignment types
Annex D Size of urgent control objects

Specifies the externally visible Basic Class Virtual Terminal Service within the OSI Application Layer.

This International Standard defines, in an abstract way, the externally visible Basic Class Virtual Terminal Service within the OSI Application Layer in terms of a model defining the interaction between users of the service; the primitive actions and events of the service; the parameter data associated with each primitive action and event; the relationship between, and the valid sequences of, these actions and events. The service defined in this International Standard is that which is provided by the OSI Basic Class Virtual Terminal Protocol (in conjunction with the Association Control Service Element and the Presentation Service) and which may be used by any user including other Application Service Elements. The relationship between the standards for Virtual Terminal Service, Virtual Terminal Protocol, ACSE, Presentation Layer Service and the user of the Virtual Terminal Service is shown in figure1. This International Standard also defines two standard default virtual terminal environment profiles and describes the form of registered virtual terminal environment profiles and control objects. Virtual terminal environment profiles define sets of virtual terminal environment parameters for use in the establishment of virtual terminal associations and subsequent negotiation. This International Standard also defines a structure of ASN.1 Object Identifiers for the objects defined in this International Standard and for use in a register of virtual terminal objects. Figure1 Relationship of this International Standardto other OSI Application Layer Standards This International Standard does not specify individual implementations or products, nor does it constrain the implementation of entities and interfaces within a computer system. There is, therefore, no requirement for conformance to this International Standard. This International Standard applies to interactive applications requiring terminal oriented communication expressed in terms of the transmission and manipulation of graphical images having the following characteristics: the images are composed of character-box graphic elements organised into a one, two or three dimensional structure; attributes may be associated with any graphic element to qualify its mode of display. Control information for the communication can be modelled using virtual terminal control objects, and multiple devicescan be modelled using virtual terminal device objects linked to the other virtual terminal objects.