PRODUCT NAME: DECnet/SNA VMS Application                       SPD 26.86.04
              Programming Interface, Version 2.3

DESCRIPTION

The DECnet/SNA VMS Application Programming Interface (API) is a layered 
software product that allows user-written applications running on suitably 
configured VMS systems within a DECnet network or on suitable VMS systems 
within a VMS/SNA environment to exchange information with cooperating 
applications on an IBM host. The API software exists in the VMS system as a 
shareable image. Access between the cooperating DIGITAL and IBMROF
ROIBM is a registered trademark of International Business Machines, Inc.
F applications 
takes place via the DECnet/SNA Gateway or via VMS/SNA software.

Features

The DECnet/SNA VMS Application Programming Interface (API) is a collection of 
subroutines designed to provide an easy-to-use interface for the VMS 
application programmer who has a specific need to interface to an IBM 
application subsystem. It supports many different types of sessions between VMS 
applications and applications running in an IBM host. 

This product implements all of the path control layer, and portions of the 
transmission and data flow control layers of SNA for the VMS user. The 
interface supports a number of differing applications each using the SNA 
function management, data flow control, and transmission control layers in its 
own way. It is not limited to supporting a particular application, such as 3270 
terminals or RJE workstations; the supported session types are Logical Unit 
Types 0, 1, 2, and 3, using the FM and TS profile types 3 and 4, described in 
the product documentation. 

The API provides extensive parameter checking, state machine management, and 
other high level services, relieving the VMS application programmer of tedious 
protocol details such as state machine processing or ``standard'' SNA message 
format checking. The interface appears to the VMS application as a set of 
subroutines that it calls to request the following operations: 

oo Establish an SNA session with an application running on an IBM host

oo Respond to a session request initiated by an IBM application

oo Re-establish a session if the connection is broken

oo Disconnect from a session

oo Receive messages from an IBM host on the normal or expedited flow

oo Send messages to an IBM host on the normal or expedited flow

oo Provide positive or negative responses to messages transmitted from an IBM 
  host

Asynchronous Event Notification

The API product provides a mechanism for a VMS user application to receive 
control when an asynchronous ``network event'' occurs such as the disconnection 
of a DECnet logical link, an SNA circuit failure, or the receipt of an Unbind 
Type 2 from IBM. The VMS application is called at a notification entry point 
defined by the application at connection time; an indication of the event that 
occurred is reported. 

SNA Functions

The API provides VMS applications with access to the SNA functions performed by 
either the DECnet/SNA Gateway or VMS/SNA software. These include SNA path 
control functions, data link control functions, and upper-level functions such 
as checking access information. The API provides assistance with some functions 
such as brackets and chaining. In addition, the API product supports negotiable 
binds and handles exception responses for the user application. (For complete 
details about which SNA functions are provided by this product, refer to the 
product documentation.) 

The application must provide the remaining SNA functions it requires. For 
example, the application must be designed to: 

oo Process all FMD layer protocols

oo Take into account all data flow control and session control request/response 
  units

oo Keep track of any ``states'' relevant to the application

oo Translate between ASCII and EBCDIC and vice versa

oo Parse the bind request

oo Respond to request units

Basic and Extended Modes

The DECnet/SNA Application Interface (Version 2.3) can be used in either basic 
or extended mode (it cannot be used in both modes simultaneously). In basic 
mode, VMS applications written for the Version 1.x product are compatible with 
this product's new version, provided that they ran successfully with the 
earlier version. 

Extended mode subroutines are layered on the basic mode subroutines, providing 
VMS programmers with an easier-to-use interface into the SNA environment. Some 
additional services the extended mode provides for the VMS programmer include 
chaining, state machine checking, building request and response headers, and 
implementing the transmission control and data flow control of SNA sessions for 
the user. 

For additional details of the two modes of operation, refer to the product 
documentation. 

User Interface

Users of the DECnet/SNA VMS API should be experienced VMS application 
programmers. They can use any of the VMS programming languages which conform to 
the VMS Calling Standard to create application programs which interact with 
application programs on an IBM system. The user documentation provides example 
programs written in the following languages: 

oo MACRO-32

oo VAX C

oo VAX COBOL

oo VAX FORTRAN

oo VAX PASCAL

oo VAX PL/I

Users of this product should be familiar with SNA and have some knowledge of 
the type of logical unit that will be used. 

SOURCE CODE

Sources of message files are available only for translation to languages other 
than English.  Source Code will not be distributed for general purposes.

INSTALLATION

Only experienced customers should attempt installation of this product. DIGITAL 
recommends that all other customers purchase DIGITAL's Installation Services.  
These services provide for installation of the software product by an 
experienced DIGITAL Software Specialist. 

Customer Responsibilities

Before DIGITAL installation of the software the customer must:
     
oo Have previously installed all requisite hardware including terminals and 
  DECnet/SNA gateway products.

oo Obtain, install, and demonstrate as operational any modems and other 
  equipment and facilities necessary to interface to DIGITAL's communications 
  equipment.   

oo Have generated, to DIGITAL's satisfaction, any necessary IBM host software 
  that will be communicating with the DECnet/SNA gateway or VMS/SNA and the 
  Application Programming Interface product.

oo Make available for a reasonable period of time, as mutually agreed by DIGITAL 
  and the customer, all hardware, communications facilities, and terminals that 
  are to be used during installation.

Delays caused by any failure to meet these responsibilities will be charged at 
the prevailing rate for time and materials. 

Successful use of this product requires that:

oo The customer must be prepared to work with both DIGITAL and IBM systems 
  personnel to coordinate the pre-installation activities.

oo The customer should be capable of modifying IBM component generation 
  parameters to support either the DECnet/SNA gateway or VMS/SNA and the 
  Application Interface software.


WARRANTY LIMITATIONS
         
IBM Supported Configurations
         
This software has been tested and is warranted against IBM System/370 (includes 
30xx and 43xx series) class processor systems configured with the following IBM 
software.  While this software may function correctly with other IBM software 
and equipment, and with software other than that supported by IBM, DIGITAL 
cannot offer its standard warranty for this software unless it has been tested 
with such equipment and software configurations. 
       
The following list shows the configurations with which the software has been 
tested and is warranted:

+-----------------------------------------------------------------------+
| Software Product				 |  Version  | Release  |
+-----------------------------------------------------------------------+
|IBM MVS Environment				 	     		|
|						 	     		|
+-----------------------------------------------------------------------+
|MVS/SP						 |     1     |  3.6	|
|						 |     	     |  3.7 	|
|						 |     2     |  1.5	|
|						 |	     |  1.7 	|
|						 |	     |  2.0	|
+-----------------------------------------------------------------------+
|TSO/E/XA					 |	     |  3.0	|
|						 |	     |  4.0	|
+-----------------------------------------------------------------------+
|ISPF/MVS					 |     2     |  2.0	|
|						 |	     |  3.0	|
+-----------------------------------------------------------------------+
|ISPF/PDF					 |     2     |  2.0	|
|						 |	     |  3.0	|
+-----------------------------------------------------------------------+
|IMS						 |     2     |  1.0 	|
|						 |	     |  3.0	|
+-----------------------------------------------------------------------+
|CICS/OS/MVS					 |     1     |  6.1 	|
|						 |	     |  7.0	|
+-----------------------------------------------------------------------+
|NCCF						 |     2     |  2.0     |
+-----------------------------------------------------------------------+
|NETVIEW					 |     1     |  1.0	|
|						 |	     |  2.0	|
+-----------------------------------------------------------------------+
|IBM VM Environment				 	       		|
+-----------------------------------------------------------------------+
|VM/SP						 |     1     |  4.1     |
|						 |	     |  5.0	|
+-----------------------------------------------------------------------+
|CMS						 |     	     |  4.1	|
|						 |	     |  5.0	|
+-----------------------------------------------------------------------+

+-----------------------------------------------------------------------+
| Software Product				 |  Version  | Release  |
+-----------------------------------------------------------------------+
|ISPF/VM					 |     2     |  2.0  	|
+-----------------------------------------------------------------------+
|ISPF/PDF					 |     2     |  2.0  	|
+-----------------------------------------------------------------------+
|NCCF						 |     2     |  1.0 	|
+-----------------------------------------------------------------------+
|NETVIEW					 |     1     |  1.0 	|
|						 |	     |  2.0	|
+-----------------------------------------------------------------------+
|IBM DOS/VSE Environment			 	      		|
+-----------------------------------------------------------------------+
|VSE/SP						 |     2     |  1.6 	|
+-----------------------------------------------------------------------+
|VSE/ICCF					 |     2     |  1.0 	|
+-----------------------------------------------------------------------+
|ISPF/VSE					 |           |  1.0 	|
+-----------------------------------------------------------------------+
|ISPF/PDF					 |     	     |  1.0     |
+-----------------------------------------------------------------------+
|CICS/DOS/VS					 |     1     |  6.0	|
+-----------------------------------------------------------------------+
|NCCF						 |     2     |  2.0   	|
+-----------------------------------------------------------------------+

Since the introduction of this software, other configurations may have been 
tested.  Please contact your local DIGITAL office for up-to-date information 
regarding listed configurations.

PREREQUISITE SUPPORT

A Network Profile and a DECnet Customer Support Plan (where appropriate) must 
be prepared jointly by DIGITAL and the customer covering all VMS nodes that 
wish to install the Application Interface product.

In order for this product to be DIGITAL supported, the customer must have a 
DIGITAL supported DECnet/SNA gateway or VMS/SNA configuration. 

To have a DIGITAL supported DECnet/SNA gateway configuration or VMS/SNA 
configuration, purchase of the Gateway Orientation/Installation Service 
(QSF0X-SZ) is REQUIRED in conjunction with the customer's first purchase of a 
DECnet/SNA gateway.

HARDWARE REQUIREMENTS
  
VAX, MicroVAX or VAXstation configuration as specified in the System Support 
Addendum (SSA 26.86.04-x).

oo Any properly configured DECnet/SNA gateway system as specified in the System 
  Support Addendum (SSA 26.86.04-x).

SOFTWARE REQUIREMENTS*

In a DECnet/SNA Gateway Environment:

oo VMS Operating System

oo DECnet-VAX 

In a VMS/SNA Environment:

oo VMS Operating System

oo VMS/SNA Software 

The DECnet/SNA VMS Application Programming Interface software requires one of 
the following products:

oo VMS/SNA
oo DECnet/SNA Gateway-CT
oo DECnet/SNA Gateway-ST
oo DECnet/SNA Gateway

* Refer to the System Support Addendum for availability and required versions 
  of prerequisite/optional software (SSA 26.86.04-x).

ORDERING INFORMATION

Software Licenses: QL-455A*-**
Software Media: QA-455A*-**
Software Documentation: QA-455AA-GZ
Software Product Services: QT-455A*-**

* Denotes variant fields. For additional information on available licenses, 
  services and media refer to the appropriate price book.

SOFTWARE LICENSING

This software is furnished under the licensing provisions of DIGITAL's Terms 
and Conditions.  For more information about DIGITAL's licensing terms and 
policies, contact your local DIGITAL office.

LICENSE MANAGEMENT FACILITY SUPPORT

This layered product supports the VMS License Management Facility.  License 
units for this product are allocated on a CPU-capacity basis.

For more information on the License Management Facility, refer to the VMS 
Operating System Software Product Description (SPD 25.01.xx) or the License 
Management Facility manual of the VMS Operating System documentation set.

For more information about DIGITAL's licensing terms and policies, contact your 
local DIGITAL office.

SOFTWARE PRODUCT SERVICES

A variety of service options are available.  For more information on these or 
other services, please contact your local DIGITAL office. 

SOFTWARE WARRANTY

Warranty for this software product is provided by DIGITAL with the purchase of 
a license for the product as defined in the Software Warranty Addendum of this 
SPD.


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