Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!linac!att!ucbvax!hls.com!nestor
From: nestor@hls.com ("Nestor A. Fesas")
Newsgroups: comp.protocols.tcp-ip.ibmpc
Subject: Re:  Question about packet, NDIS, Clarkson, BYU, etc
Message-ID: <9105071845.AA29657@lanslide.hls.com>
Date: 7 May 91 18:45:44 GMT
References: <9105070330.AA05948@alw.nih.gov>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 35

> 
> >   ....  As a practical matter, LAN Manager requires an NDIS driver, so NDIS
> >   isn't going away.  And I'm a crazy man, so the packet drivers aren't going
> >   away either.
> >
> > Regardless of your sanity, which I wouldn't have questioned in any case, you
> > can't unbind (disconnect) from a v1 NDIS driver except by re-booting.  This
> > means that things like KA9Q and PC-IP whose protocol stack isn't a separate
> > TSR will never be able to use NDIS directly unless v2 drivers start to appear.
> 
> 3Com has something they call Demand Protocol Architecture, which allows
> protocol stacks to be loaded and unloaded in an NDIS environment.  Is
> this something layered on top of NDIS then, so that not all NDIS stacks
> support it?
> 

I'm not sure how 3Com does it, but we do it in just this fashion. Our ProLINC
software was originally designed to operate over a proprietary interface that
we call MPD (multiple protocol driver). MPD supports the concept of "unbinding"
stacks from the driver. As such, when we produced our MPD to NDIS converter,
this functionality was retained. In a nut shell, the MPD binds with the NDIS
driver and begins monitoring incoming frames. Upon arrival of a frame, it is
handed to the target protocol - if loaded. Otherwise, the MPD returns error
code 03h (FRAME_NOT_RECOGNIZED) to the NDIS driver. The driver is then free to
pass the frame on to the next protocol.

I suspect that the Packet Driver to NDIS converter can do something similar.
Maybe someone else can comment further.

...............................................................................

Nestor A. Fesas, Jr.					Hughes LAN Systems
voice: (415) 966-7473					1225 Charleston Road
fax:   (415) 960-3738					Mountain View, CA 94043
inet:  nestor@hls.com					Mailstop 7