KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q156479: INFO: Differences Between DLC on Windows 95 and Windows NT

Article: Q156479
Product(s): Microsoft Windows 95.x Retail Product
Version(s): 3.5,4.0
Operating System(s): 
Keyword(s): kbnetwork kbAPI kbDLC kbOSWinNT400 kbSDKPlatform kbOSWin95 kbOSWinNT350 kbGrpDSNet
Last Modified: 19-FEB-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows 95 
- Microsoft Windows NT Workstation versions 3.5, 4.0 
-------------------------------------------------------------------------------

SUMMARY
=======

This article describes the major differences between the Win32 Data Link Control
(DLC) API as implemented on Windows 95 and Windows NT. It assumes familiarity
with the DLC protocol and the relevant specification documents. It also assumes
familiarity with the following Microsoft Knowledge Base article that describes
the differences between Windows NT DLC and the IBM Specifications for OS/2
1.xx:

  Q156081 Differences between Data Link Control APIs on Windows NT & DOS

MORE INFORMATION
================

The differences between Windows 95 and Windows NT DLC are as follows:

1. The Windows 95 API continues to use the CCB Application ID field. In Windows
  NT and DLCAPI.H, this field is defined as uchReserved2 in the LCC_CCB
  structure and is commented as reserved for DLC DLL. A Windows 95 application
  must use this field as defined for OS/2 EE. That is:

   - Issue a DIR.OPEN.ADAPTER command with this CCB set to zero. The DLC driver
     will set this field to an Application ID value.

   - This Application ID must be used in subsequent CCB requests by setting
     uchReserved2 to this value.

  This difference is necessary because Windows 95 does not have support for the
  security mechanisms used by Windows NT in lieu of the application ID.

  See The IBM LAN Technical Reference Manual for more information.

2. The fields uchReserved1 and uchReserved3 must not be used by an application
  under any circumstances.

3. NT-specific extensions such as security, multiple processors, or
  international character strings are not supported.

4. Windows 95 continues to support the completion method of polling (busy
  looping) on the CCB's return code (uchDlcStatus in the LLC_CCB structure).
  This method is not reliable on Windows NT and an application that uses it on
  Windows 95 may not work on Windows NT.

5. Windows 95 allows a DIR.STATUS command to be issued before a DIR.OPEN.ADAPTER
  CCB. NT does not allow this. You should be aware of this when writing
  cross-platform applications.

6. Windows 95 does not support:

   - Multiple logical adapters.

   - TRANSMIT.FRAMES.CCB.

   - Direct station support that is global to all applications.

7. The Windows 95 802.2 implementation does support CCB 1's or a 16-bit DOS
  interface.

8. An application must issue a BUFFER.CREATE command before issuing any of the
  following CCBs:

  BUFFER.FREE              DLC.OPEN.SAP         XMIT.I.FRAME
  BUFFER.GET               DLC.OPEN.STATION     XMIT.DIR.FRAME
  DIR.CLOSE.DIRECT         DLC.REALLOCATE       XMIT.TEST.CMD
  DIR.OPEN.DIRECT          DLC.RESET            XMIT.UI.FRAME
  DLC.CLOSE.SAP            DLC.STATISTICS       XMIT.XID.CMD
  DLC.CLOSE.STATION        READ                 XMIT.XID.RESP.FINAL
  DLC.CONNECT.STATION      READ.CANCEL          XMIT.XID.RESP.NOT.FINAL
  DLC.FLOW.CONTROL         RECEIVE
  DLC.MODIFY               RECEIVE.CANCEL

REFERENCES
==========

1. IBM LAN Technical Reference SC30-3383. This describes the basic set of CCB2
  functions as used by OS/2 EE.

2. DLCAPI.H

3. For more information, please see the following article in the Microsoft
  Knowledge Base:

  Q156081 Differences between Data Link Control APIs on Windows NT & DOS

Additional query words:

======================================================================
Keywords          : kbnetwork kbAPI kbDLC kbOSWinNT400 kbSDKPlatform kbOSWin95 kbOSWinNT350 kbGrpDSNet 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWin95search kbZNotKeyword3
Version           : :3.5,4.0
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.