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 2000 operating system
Windows XP operating system
Windows Server 2003 operating system
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
Windows Server 2025 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 2.3.1: The ReservedData1 field is not used by the Callback Control Protocol.
<2> Section 2.3.1: The ReservedData2 field is not used by the Callback Control Protocol.
<3> Section 3.1.1: Windows uses a Retry count value of 10; that is, after 10 retransmissions, the subsequent retransmission timer expiry will cause the CBCP phase to be completed with a failure.
<4> Section 3.1.2: Windows selects the timer value based on the speed of the underlying link. The following table specifies the link speed and the retransmission timer value used.
|
Link speed (bps) <= |
Retransmission timer (seconds) |
|---|---|
|
1200 |
7 |
|
2400 |
5 |
|
9600 |
3 |
|
Others |
2 |
<5> Section 3.1.5.3: Windows selects the callback type in the order user-specifiable, pre-specified, or administrator-specifiable, and finally no callback based on the options provided by the answerer.
<6> Section 3.2.2: Windows selects the timer value based on the speed of the underlying link. The following table specifies the link speed and the retransmission timer value used.
|
Link speed (bps) <= |
Retransmission timer (seconds) |
|---|---|
|
1200 |
7 |
|
2400 |
5 |
|
9600 |
3 |
|
Others |
2 |