6 Appendix A: Product Behavior

The information in this specification is applicable to the following Microsoft products or supplemental software. References to product versions include updates to those products.

  • Windows Vista operating system

  • Windows Server 2008 operating system

  • Windows 7 operating system

  • Windows Server 2008 R2 operating system

  • Windows 8 operating system

  • Windows Server 2012 operating system

  • Windows 8.1 operating system

  • Windows Server 2012 R2 operating system

  • Windows 10 operating system

  • Windows Server 2016 operating system

  • Windows Server operating system

  • Windows Server 2019 operating system

  • Windows Server 2022 operating system

  • Windows 11 operating system

Exceptions, if any, are noted in this section. If an update version, service pack or Knowledge Base (KB) number appears with a product name, the behavior changed in that update. The new behavior also applies to subsequent updates unless otherwise specified. If a product edition appears with the product version, behavior is different in that product edition.

Unless otherwise specified, any statement of optional behavior in this specification that is prescribed using the terms "SHOULD" or "SHOULD NOT" implies product behavior in accordance with the SHOULD or SHOULD NOT prescription. Unless otherwise specified, the term "MAY" implies that the product does not follow the prescription.

<1> Section 1.3: In Windows Vista and Windows Server 2008, support for the client-side elements of this protocol is available only with the installation of the Background Intelligent Transfer Service (BITS) (see [MC-BUP]) via the Windows Management Framework (WMF). Support for the server-side elements of this protocol is not available. For more information, see [MSDN-BITS].

<2> Section 1.7: Windows 7 supports version 1.0. Otherwise, Windows clients support version 2.0.

<3> Section 2.1: In Windows Server 2008 R2, the hosted cache listens on port 443 by default. Otherwise, in applicable Windows Server releases, the hosted cache listens on both port 80 and port 443 by default.

<4> Section 2.2.1.1: Windows 7 supports version 1.0. Otherwise, Windows clients support version 2.0.

<5> Section 2.2.1.1: In Windows 7, the value of MajorVersion is 0x01. Otherwise, in Windows clients the value of MajorVersion is 0x02.

<6> Section 3.1: In Windows Vista and Windows Server 2008, support for the server-side elements of this protocol is not available.

<7> Section 3.2: In Windows Vista and Windows Server 2008, support for the client-side elements of this protocol is available only with the installation of the Background Intelligent Transfer Service (BITS) in the Windows Management Framework. For more information, see [MSDN-BITS].

<8> Section 3.2.1: In applicable Windows Server releases, the values of the content tag can be the following:

  • The ASCII string "WinINet" is used by clients of the WinInet APIs. For more information see [MSDOCS-WinINet].

  • The ASCII string "WebIO" is used by clients of the WebIO APIs (a WebIO server provides Internet to X10 power line control (PLC) gateway to control devices commonly used in home automation).

  • The ASCII string "BITS-4.0" is used by the Background Intelligent Transfer Service. See [MSDN-BITS] and [MS-BPCR].

  • The binary byte array {0x35, 0xDB, 0x04, 0x5D, 0x14, 0x23, 0x45, 0x53, 0xA0, 0x51, 0x0D, 0xC2, 0xE1, 0x5E, 0x6C, 0x4C} is used by the SMB stack.

The higher-layer component on cache servers hosted by Windows tracks performance statistics for each of these values and categorizes all other values as "Other".

<9> Section 3.2.4: Windows invokes this protocol after 20% of new blocks of a segment have been received from the content server.