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lkcl16oct2005: hi indolering, okay: the OSI model goes kinda out the window a bit, because of the emulation side. NetBIOS _used_ to be layer 2: some companies, such as lanier business systems even produced NetBIOS network cards - real hardware!
but NetBIOS over TCP/UDP definitely makes it now "layer 2".
then you have SMB as a service on that.
_then_ you have MSRPC using the SMB service as a transport (ncacn_np)
_then_ you have MSRPC services - running not just on the ncacn_np transport, but also over ncacn_nb - netbios :) - and ncacn_ip_tcp - over TCP/IP.
it's all a bit grey as to what's actually what layer - references the OSI model i believe would just add confusion.
if you still believe it would help, even though the areas are a bit grey - let me know.
l.