Winsock

Source: Wikipedia, the free encyclopedia.
Not to be confused with Windsock.

In

FTP client or a web browser) and the underlying TCP/IP protocol stack. The nomenclature is based on the Berkeley sockets API used in BSD
for communications between programs.

Background

Early Microsoft operating systems, both MS-DOS and Microsoft Windows, offered limited networking capability, chiefly based on

MIT, FTP Software, Sun Microsystems, Ungermann-Bass, and Excelan, introduced TCP/IP products for MS-DOS, often as part of a hardware/software bundle. When Windows 2.0 was released, these vendors were joined by others such as Distinct and NetManage
in offering TCP/IP for Windows.

The drawback faced by all of these vendors was that each of them used their own API (Application Programming Interface). Without a single standard programming model, it was difficult to persuade independent software developers to create networking applications which would work with any vendor's underlying TCP/IP implementation. Add to this the fact that end users were wary of getting locked into a single vendor and it became clear that some standardization was needed.

The Windows Sockets project had its origins in a Birds Of A Feather session held at Interop '91 in San Jose on October 10, 1991.

IETF
or establishing a non-profit foundation. In the end, it was decided that the specification would simply be copyrighted by the five authors as (unaffiliated) individuals.

All the participating developers resisted the shortening of the name to simple Winsock for a long time,[

DLL file was present on a system would provide full TCP/IP protocol support.[citation needed
]

Technology

The Windows Sockets API specification defines two interfaces: the

TCP/IP
protocol stack with all recent versions of Windows, and there are no significant independent alternatives. Nor has there been significant interest in implementing protocols other than TCP/IP.

Windows Sockets code and design are based on

moniker
WSA, e.g. WSASend() for sending data on a connected socket.

However it was a design goal of Windows Sockets that it should be relatively easy for developers to port socket-based applications from

pseudo terminals and the fork system call
, and reproducing such functionality in Windows was problematic. Within a relatively short time, porting gave way to the development of dedicated Windows applications.

Specifications

  • Version 1.0 (June 1992) defined the basic operation of Winsock. It was kept very close to the existing interface of Berkeley sockets to simplify porting of existing applications. A few Windows-specific extensions were added, mainly for asynchronous operations with message-based notifications.
Although the document didn't limit support to TCP/IP, TCP and UDP were the only protocols explicitly mentioned. Most vendors only delivered TCP/IP support, although Winsock from
DECNet
support as well.

Updates in Windows 8

Windows 8 includes the "RIO" (Registered IO) extensions for Winsock.[2] These extensions are designed to reduce the overhead of the user to kernel mode transition for the network data path and the notification path, but use the rest of the regular Windows TCP and UDP stack (and uses existing network cards). The setup path (for example, the "connect" function) is unchanged from the regular Winsock path.

Implementations

Microsoft implementations

  • Microsoft did not supply an implementation of Winsock 1.0.
  • Version 1.1 of Winsock was supplied in an add-on package (called Wolverine) for Windows for Workgroups (code named Snowball). It was an integral component of Windows 95 and Windows NT from versions 3.5 and onwards (the initial commercially available version of Windows NT, version 3.1, included only a proprietary and quite incomplete implementation of TCP/IP based on the AT&T UNIX System V "STREAMS" API [citation needed]).
  • Version 2.1 of Winsock was supplied in an add-on package for Windows 95. It was an integral component of Windows 98, Windows NT 4.0, and all subsequent Windows releases. (Microsoft did not supply implementations of Winsock 2 for Windows 3.x or Windows NT 3.x.)
  • Recent versions of Winsock 2.x have been delivered with new Windows releases or as part of service packs.
  • Winsock 2 is extensible by a mechanism known as a Layered Service Provider (LSP). Winsock LSPs are available for a wide range of useful purposes, including Internet parental controls, web content filtering, QoS etc. The layering order of all providers is kept in the Winsock Catalog. In previous versions of Windows, removing a buggy LSP could result in corruption of the Winsock catalog in the registry, potentially resulting in a loss of all network connectivity. Winsock in Windows XP Service Pack 2, Windows Server 2003 Service Pack 1 and all later Windows operating systems has the ability to self-heal after a user uninstalls such an LSP.

Other implementations

  • Among the other vendors offering Winsock-compliant TCP/IP and UDP/IP stacks were (alphabetically) 3Com, Beame & Whiteside, DEC, Distinct, Frontier, FTP Software, IBM, Microdyne, NetManage, Novell, Sun Microsystems and Trumpet Software International.
  • Trumpet Winsock by Peter Tattam was one of the few Winsock 1.0 implementations that could be installed under Windows 3.0, which had no built-in support for Winsock.[3][4] Trumpet was also the most popular shareware implementation of Winsock for Windows 3.x. Trumpet Winsock 5.0 is available for Windows 95/98 and Windows NT and includes a Winsock 1.1 compliant IPv6 stack for these operating systems.[5]
  • The Wine project contains a source and binary compatible reimplementation of Winsock on top of the BSD sockets API.

See also

References

  1. ^ "Winsock Version 1.0 Rev.A". Retrieved 8 October 2020.
  2. ^ "New techniques to develop low-latency network apps". Channel 9.
  3. ^ "Mosaic turns 20: Let's fire up the old girl, show her the web today". theregister.co.uk.
  4. ^ "What It Was Like To Build A World Wide Web Site In 1995". fastcompany.com. 18 November 2015.
  5. ^ "Downloads". www.trumpet.com.au.

External links

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