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Q151210: Q&A: Types Of Socket Applications Supported By Microsoft

Article: Q151210
Product(s): Microsoft Windows NT
Version(s): 3.11b,3.5,3.51
Operating System(s): 
Keyword(s): 
Last Modified: 31-OCT-2001

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The information in this article applies to:

- Microsoft Windows NT Workstation versions 3.5, 3.51 
- Microsoft Windows NT Server versions 3.5, 3.51 
- Microsoft LAN Manager 
- Microsoft TCP/IP-32 for Windows for Workgroups, version 3.11b 
- Microsoft Windows for Workgroups 
- Microsoft Windows 95 
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SUMMARY
=======

This article contains questions and answers regarding the different types of
socket application supported by MS-DOS and the Microsoft Windows operating
system.

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

What is a socket application?

A socket interface was first provided with Berkeley UNIX (BSD) in the eighties.
It was designed as a network interprocess communication (IPC) mechanism for the
built-in TCP/IP. A socket defines a bi-directional end point for combination
between processes.

A socket has three primary components:

  The interface to which it is bound
  The port number to which it will send or receive data
  The type of socket--either stream or datagram

In TCP/IP, the interface is the IP address of the host. The port number is the
software process address. In IPX/SPX, the interface is the combination of the
IPX network ID and the MAC address of the network interface. The port number is
the software process address (IPX socket number).

A server application listens on a well-known port over all installed network
interfaces. A client generally initiates communication from a specific interface
from any available port.

What is Windows Sockets?

The Windows Socket (WinSock) specification defines a network programming
interface for Microsoft Windows that is based on the Socket interface
popularized in Berkeley Unix. The WinSock API is a library of functions that
implement the Windows Socket specification. WinSock augments the Berkeley socket
implementation by adding Windows-specific extensions to support the
message-driven nature of Windows operating systems.

There are a few other proprietary windows socket APIs (WSOCKETS, and WIN_SOCK).
For more information see the following article in the Microsoft Knowledge Base:

Q98599Differences Among WIN_SOCK.DLL, WSOCKETS.DLL, and WINSOCK.DLL

These are not encouraged APIs and do NOT implement the Windows Sockets API
standard.

What is WINSOCK.DLL?

WINSOCK.DLL is a dynamic-link library (DLL) that provides Windows Sockets version
1.1 API for TCP/IP Windows Socket applications. WINSOCK.DLL is offered in
current version of all Microsoft TCP/IP stacks:

  MS-DOS TCP/IP for Lanman 2.2C
  MS-DOS TCP/IP for Microsoft Network 3.0 Clients
  Microsoft TCP/IP for Windows for Workgroups
  Microsoft TCP/IP-32 for Windows for Workgroups
  Microsoft TCP/IP for Windows NT 3.5x
  Microsoft TCP/IP for Windows 95

For additional information about Microsoft TCP/IP protocol comparison, see the
following article in the Microsoft Knowledge Base:

Q94069Microsoft TCP/IP Protocol Comparison and FAQ

What version of the WinSock specification does WINSOCK.DLL comply with?

Microsoft WINSOCK.DLL complies with Windows Socket Specification version 1.1.
Support for previous versions of the Sockets specification is not provided.
WINSOCK.DLL does not provide support for Raw Sockets(SOCK_RAW), DOS Sockets, or
vendor-specific implementations.

For instruction about downloading the WinSock specification from Microsoft, see
the following article in the Microsoft Knowledge base:

Q85965Microsoft Socket API Specification version

What is WSOCK32.DLL?

WSOCK32.DLL is a dynamic-link library (DLL) that provides Windows Sockets API for
32-bit TCP/IP Windows Socket applications and 32-bit IPX/SPX Windows Socket
Applications. WSOCK32.DLL is offered in Windows NT and 95.

Can Microsoft WINSOCK.DLL be used with third-party TCP/IP stacks?

No. WINSOCK.DLL and WSOCK32.DLL will be provided by the vendor providing the
TCP/IP stack. The DLL and the protocol stack implementation cannot be mixed and
matched with other TCP/IP and DLL implementations. For example, you cannot use
WINSOCK.DLL provided by Microsoft with FTP's TCP/IP stack or vice versa.

What type of Socket applications are supported by MS-DOS TCP/IP stacks?

MS-DOS TCP/IP for Lanman 2.2c and Microsoft Network Clients 3.0 support DOS
Socket application and WinSock 1.1 application. Sockets.exe in MS-DOS TCP/IP is
a terminate-and-stay-resident (TSR) program; it allows MS-DOS socket
applications to run if they've been written with the Microsoft TCP/IP Sockets
Development Kit Version 1.0, using the DOS Socket Library (DOS_SOCK.LIB)
available in the Development Kit. WSOCKETS.DLL is provided in Lanman 2.2 SDK to
make Windows calls look as they do in MS-DOS.

While the 16-bit MS-DOS TCP SDK is still available (through Microsoft Developer
Support), it is no longer supported by Microsoft and is not guaranteed to work.
The user accepts full responsibility regarding the use of the SDK.

The SOCKETS.EXE and WSOCKETS.DLL do NOT implement the Windows Sockets API
standard.

In order for a Windows Socket application to function with MS-DOS TCP/IP,
SOCKETS.EXE must be loaded before Windows startup and WINSOCK.DLL must exist in
the application search path.

Is it possible to run a 32-bit Windows Socket application with Windows 3.x?

Yes. Win32s 1.1 contains a thunking layer that converts 32-bit Windows Sockets
calls (using WSOCK32.DLL) to 16-bit Windows Sockets calls (using WINSOCK.DLL).

Does a Windows Sockets application work over any protocols other than TCP/IP?

Yes. In Windows NT and 95, sockets support is also extended to IPX/SPX. Both
16-bit and 32-bit IPX/SPX Windows sockets are supported over NWLINK in Windows
NT and 95.

Does MS Network Client 3.0 support MS-DOS/Windows IPX/SPX Socket applications?

No. MS-DOS/Windows IPX/SPX Socket applications running in a Virtual machine of
Windows 95 can be interfaced with NWLINK via WSOCK.VXD. WSOCK.VXD supports
16-bit Windows Sockets application over 32-bit TCP/IP and IPX/SPX Windows
Socket.

Additional query words:

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Keywords          :  
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search kbAudDeveloper kbWin95search kbTCPIPSearch kbLanManSearch kbWFWSearch kbZNotKeyword3 kbTCPIP311b
Version           : :3.11b,3.5,3.51

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