IPPROTO_TCP Socket Options

The following table describes IPPROTO_TCP socket options that apply to sockets created for the IPv4 and IPv6 address families (AF_INET and AF_INET6) with the protocol parameter to the socket function specified as TCP (IPPROTO_TCP). See the getsockopt and setsockopt function reference pages for more information on getting and setting socket options.

To enumerate protocols and discover supported properties for each installed protocol, use the WSAEnumProtocols, WSCEnumProtocols, or WSCEnumProtocols32 function.

IPPROTO_TCP Socket Options

Option	Get	Set	Optval type	Description
TCP_BSDURGENT	yes	yes	DWORD (boolean)	If TRUE, the service provider implements the Berkeley Software Distribution (BSD) style (default) for handling expedited data. This option is the inverse of the TCP_EXPEDITED_1122 option. This option can be set on the connection only once. Once this option is set on, this option cannot be turned off. This option is not required to be implemented by service providers. The option is enabled (set to TRUE) by default.
TCP_EXPEDITED_1122	yes	yes	DWORD (boolean)	If TRUE, the service provider implements the expedited data as specified in RFC-1222. Otherwise, the Berkeley Software Distribution (BSD) style (default) is used. This option can be set on the connection only once. Once this option is set on, this option cannot be turned off. This option is not required to be implemented by service providers.
TCP_NODELAY	yes	yes	DWORD (boolean)	Enables or disables the Nagle algorithm for TCP sockets. This option is disabled (set to FALSE) by default.

 

Windows Support for IPPROTO_TCP options

Option	Windows 7	Windows Server 2008	Windows Vista	Windows Server 2003	Windows XP	Windows 2000	Windows NT4	Windows 9x/Me
TCP_BSDURGENT	x	x	x	x	x	x	x
TCP_EXPEDITED_1122	x	x	x	x	x	x
TCP_NODELAY	x	x	x	x	x	x	x

 

Remarks

On the Microsoft Windows Software Development Kit (SDK) released for Windows Vista and later, the organization of header files has changed and IPPROTO_TCP level is defined in the Ws2def.h header file which is automatically included in the Winsock2.h header file. The IPPROTO_TCP socket options, with the exception of TCP_BSDURGENT, are defined in the Ws2ipdef.h header file which is automatically included in the Ws2tcpip.h header file. The TCP_BSDURGENT option for historic reasons is defined in the Mswsock.h header file. The Ws2def.h and Ws2ipdef.h header files should never be used directly.

Requirements

Send comments about this topic to Microsoft

Build date: 11/29/2012