PRODUCT NAME: DECnet/SNA VMS Distributed Host        SPD 26.71.03
              Command Facility, Version 1.2

DESCRIPTION

DECnet/SNA VMS Distributed Host Command Facility (DHCF) is a 
VMS layered software product which is used in conjunction with 
the DECnet/SNA gateway products. It allows suitably configured VMS systems 
within a DECnet network to be accessed from IBM (r) host-controlled 
327x display stations in a Systems Network Architecture (SNA) 
networking environment. Users of the IBM system gain access to VAX
systems via any of the DECnet/SNA gateway products.

In an actual IBM distributed processing environment, 3270 terminal operators 
can access, monitor, and control remote IBM 8100 Information System computers, 
suitably configured Series/1 small business computers and AS/400 systems 
using an IBM mainframe-based Program Product called Host Command Facility 
(HCF).  HCF permits a terminal on a System/370, 43xx or 30xx mainframe to 
function as if it were directly attached to the remote distributed processor.  
HCF interacts with cooperative IBM-supplied software that runs on the
remote distributed processor to provide such support.  

The 3270 terminal operator using HCF can log into the remote processor to 
invoke system services and user programs. In addition, HCF allows the terminal 
operator at a centralized Network Control Center to access the maintenance, 
service, and control functions of the remote system for problem determination, 
problem isolation, and remote system control.

DECnet/SNA VMS DHCF is another VMS-based access routine in the DECnet/SNA 
product set.  It is a VMS layered application that provides the software for 
VMS systems to communicate with the IBM HCF program product.  When DECnet/SNA 
VMS DHCF is installed on a VMS system, IBM 3270 terminal operators can 
access the VMS system, via a DECnet/SNA gateway, using the IBM HCF program 
product as described in the above paragraphs.  Although it may be possible 
to access non-VMS systems once the 3270 user has logged on to a VMS
processor (e.g., CTERM access to ULTRIX-based systems or PSI access to
systems via X.29), this will not be considered as a supported configuration.
DHCF is intended for use with VMS-based systems only.

DECnet/SNA VMS DHCF provides "line mode" or "glass TTY" access for the 
IBM 3270 user to the VMS system. Such access is appropriate for entering 
system and network management DCL commands in the VMS environment.  DHCF
is not intended as a general purpose full screen access mechanism to the
VMS environment.  Full screen access to VMS-based applications is 
possible only if the application uses DIGITAL's Forms Management System 
(FMS).  Certain FMS restrictions apply; refer to VAX FMS (SPD 26.10.xx)
and DECnet/SNA Gateway documentation set for full details.  

DHCF was not designed to transform ASCII escape sequences and general ANSI 
data streams into 3270 data streams.  For this reason, full screen oriented 
DIGITAL base applications such as WPS-PLUS and most applications running under 
ALL-IN-1 are inappropriate for access through DHCF.

Features

^ The DHCF user may run any VMS application that can run in 
  VMS line mode (i.e. applications that are appropriate for
  use on a DEC LAxx-type hardcopy terminal).

^ The DHCF user may have full-screen access to VMS applications 
  which are specifically designed to run with 327x terminals, 
  using DIGITAL's VAX Forms Management System (FMS). (Refer to 
  the Optional Software section of the System Support Addendum 
  for this product).

^ In IBM's terminology, DHCF allows full screen mode 
  sessions from IBM's NetView/Terminal Access Facility; OPCTL 
  (operator control) mode sessions from NetView/TAF are not 
  supported.

^ Access to HCF in either an IBM MVS or VSE/SP Operating System
  environment is supported.

^ The VMS system manager may perform the following tasks:

  - Modify the EBCDIC-to-DMCS (ASCII) translation tables
  - Modify Attention Identification (AID) key mappings

^ A DECnet/SNA gateway manager may perform the following tasks:

  - Create the configuration file required for DHCF
  - Modify the initial connect screen

^ DHCF provides support for 8-bit codes, extending ASCII into the
  Digital Multinational Character Set (DMCS)

^ The documentation specifies the IBM parameter values which are 
  required to initialize the IBM application software in order for
  communication with DHCF to occur.   Refer to the appropriate guide:
 
  - DECnet/SNA Gateway-CT Guide to IBM Parameters
  - DECnet/SNA Gateway-ST Guide to IBM Parameters
  - DECnet/SNA Guide to IBM Parameters 

^ Error messages are reported to the DHCF user in easily 
  understandable language.

User Interface

The IBM 3270 terminal user logs on to HCF running on the IBM mainframe
and enters the conventional HCF ACQUIRE command to connect to the 
DECnet/SNA gateway.  Once the connection between the mainframe and the
DIGITAL environment is established, DHCF sends an initial connect screen to 
the IBM 3270 terminal user which is similar to comparable panels 
displayed by VTAM. The DHCF user then enters the name of the 
DECnet node he or she wishes to access. When the DHCF user's request has 
been routed to the desired node, the user must log in to the VMS 
system in the usual manner.  

The DHCF software running on the VAX processor can support up to 
128 DHCF sessions, depending upon the processor size and available memory.  
The DECnet/SNA gateway products provide IBM mainframe connectivity for up to 
16 concurrent DHCF sessions.  These sessions can, of course, be accessed 
from any node in the DECnet network running DHCF software.

INSTALLATION

Customer Responsibilities

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

^  Have generated, to DIGITAL's satisfaction, any necessary IBM 
   host software that will be communicating with the DECnet/SNA 
   gateway and DHCF.

^  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:

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

^  The customer should be capable of modifying IBM component 
   generation parameters to support either the DECnet/SNA gateway 
   or DHCF.

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. 

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
                        2              1.3
                                       1.5
                                       1.7
                                       2.0

  HCF                   2              1.0
-------------------------------------------------------------
IBM DOS/VSE Environment
-------------------------------------------------------------
  VSE/SP                2              1.6
  HCF                   2              0.0
-------------------------------------------------------------

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 (where appropriate) Customer Support Plan 
covering all VMS nodes that will serve as hosts to IBM terminals 
prepared jointly by DIGITAL and the customer.

For DECnet/SNA VMS DHCF to be DIGITAL supported, the customer 
must have a DIGITAL supported DECnet/SNA gateway configuration.  

To have a DIGITAL supported DECnet/SNA gateway configuration, purchase of
the Gateway Orientation/Installation Service (QSF0x-SZ) is REQUIRED in
conjunction with the customer's first purchase of the DECnet/SNA Gateway.

HARDWARE REQUIREMENTS

VAX, MicroVAX or VAXstation configuration as specified in the System 
Support Addendum (SSA 26.71.03-x).
   
Any properly configured DECnet/SNA Gateway system as specified in the 
System Support Addendum.

SOFTWARE REQUIREMENTS *

VMS Operating System 

DECnet-VAX end node or full function node license

In a DEC MicroServer (DEMSA) or a DEC ChannelServer (DESNA) environment,
the gateway load host must have DECnet/SNA VMS Gateway Management software as
specified in the System Support Addendum (SSA 26.71.03-x).

In a DECnet/SNA Gateway (DECSA) environment, all VMS systems to which 
the DHCF software provides access must have DECnet/SNA Gateway Management 
software as specified in the System Support Addendum (SSA 26.71.03-x).

* Refer the the System Support Addendum for the availablity and 
  required versions of prerequisite software (SSA 26.71.03-x).

ORDERING INFORMATION

Software Licenses:  QL-043A*-**
Software Media:	QA-043A*-**
Software Documentation:	QA-043AA-GZ
Software Product Services: QT-043A*-**

* 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 from DIGITAL.  For more 
information 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. 


(r) IBM is a registered trademark of IBM Corporation

April 1989
BH-DE56D-TE
