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From: trier@cwlim.INS.CWRU.Edu (Stephen C. Trier)
Subject: Re: PC/NFS, Socket Libraries, TCP/IP (FAQ?)
Message-ID: <1991May30.225959.3493@usenet.ins.cwru.edu>
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Organization: Case Western Reserve Univ. Cleveland, Ohio, (USA)
References: <675518012.54@sunbrk.FidoNet>
Date: Thu, 30 May 91 22:59:59 GMT
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You've got two different issues here, or at least, you seem to be asking
two different questions.

First, you are asking about "cohabitation of NFS, WinQVTnet, and other
TCP/IP services".  This just isn't possible with today's protocol stacks.
What happens is that only one stack at a time can use the IP ethertype.
(This is enforced by the packet drivers.)  Even if the packet driver didn't
require this, how would the packet driver know which packet belonged to
which TCP/IP protocol stack?  Thus, it's a fundamental limitation on any
system, DOS, Unix, or Windows, that you can't have more than one TCP/IP
protocol suite loaded per ethernet card.

Now, you _can_ use multiple TCP/IP applications, as long as they interface
at the TCP or UDP levels.  You just need applications that will work together
and that will operate efficiently under the Windows environment.

I'm planning to solve the problem the following way -- A TCP/IP kernel is
loaded as a TSR before Windows is started.  (The same TSR provides TCP/IP
services to both DOS and Windows applications.)  Windows versions of the
normal applications (telnet, FTP, mail, and news) are created, speaking
to the kernel through a DLL.  The DLL handles the job of getting some
memory mapped in the real 640K address space, copying the data to and from
that address space, and calling the kernel to provide the protocol services.

The changes are not as bad as I had originally feared (I'm not going to
have to reimplement the whole TCP/IP stack!), but it's still going to be
a lot of work.  I _will_ have to reimplement a lot of FTP and telnet and
all of our mail and news applications.

Your dealers are going through the same steps I'm going through, except
that they may be using some more sophisticated techniques.  I don't have
the DDK, so I'm working based on what I can find in the SDK and a little
info from the last chapter of _Undocumented DOS_.

-- 
Stephen Trier                        Work: trier@ins.cwru.edu
Case Western Reserve University      Home: sct@seldon.clv.oh.us
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