As you know per previous posts on this blog, Winsock Kernel, a new transport-independent kernel mode Network Programming Interface (NPI), is available on Windows Vista and Windows Server Longhorn platforms.  On Windows Vista & Windows Server Longhorn, TDI is still supported for compatibility reasons; however, it has been implemented using a translation layer and thus its performance is sub-optimal resulting in performance degradation for TDI clients.  For this reason, as well as others (TDI on path to deprecation, etc -- see resource links below), drivers should opt to use WSK whenever possible.   

To help us understand how we can best make WSK adoption and porting from TDI to WSK straightforward, we would appreciate it if you could respond to the following questions. Responses can be sent to wskapi at

If you have an existing TDI Client driver:

1)      Which operating systems does your TDI client support (Windows XP and/or Windows Server 2003, etc)?

2)      Do you plan to port your TDI client to WSK on Windows Vista / Windows Longhorn server OR do you plan to continue to use your TDI-based driver on Windows Vista / Windows Longhorn Server?

a.       If WSK was also supported on Windows XP and/or Windows Server 2003, would your answer to question #2 above change?  If so, how?


If you are working on a new project which requires a kernel mode driver with network capabilities:

3)      Do you plan to support Windows XP / Windows 2003 with the project deliverable?  If so, would you use WSK for the project if it was available on these platforms?


Additional Requirements:

4)      Do you have any requirements (performance, etc) that would need to be met by WSK (on pre Windows Vista platforms) in order for WSK to be an option on such platforms?   

WSK Resources

Overview of WSK:

Network Programming with Winsock Kernel:

WSK MSDN Documentation:

WDK RC1 Download: See, Windows Driver Kit Program, Downloads Section

If you have any further comments or questions, please feel free to contact us at wskapi at

We look forward to your feedback.

--Mike Flasko