A friend pointed out that the Active Directory specifications are available online for those who have ever wanted to down to the details on the protocols used.

As he said “…all of it downloadable for personal reading pleasure”.

Released as part of  Microsoft Open Protocol Specifications

 

And some related protocols:

 

I suppose this is Microsoft “opening the kimono” and exposing the details on some of their technology.  Overall this is good news to those interested to be able to see this level of information.