Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!VAX.FTP.COM!jbvb
From: jbvb@VAX.FTP.COM (James Van Bokkelen)
Newsgroups: comp.protocols.tcp-ip.ibmpc
Subject: Re: some Qs on packet drivers
Message-ID: <8902241637.AA10273@vax.ftp.com>
Date: 24 Feb 89 16:37:07 GMT
References: <2109@aecom.YU.EDU>
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Organization: The Internet
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The Packet Driver was intended to do one level of demultiplexing, and all
but one of the existing drivers do that at the MAC layer (according to the
Ethertype field).  The one exception does its demultiplexing according to
the IP protocol byte.  This still uses datagrams, and is about the highest
level you can use a simple spec like the Packet Driver with.

So, nothing that exists would deal with the case you propose.  I would say
that this case isn't a particularly likely one, because it implies two TCPs
in the same machine (which has been done, but requires really odd split-level
multiplexing/demultiplexing).  If you are working with FTP's v2.0, and want
to use the NCSA user interface, I'd recommend removing the transport layer
from the NCSA, and re-writing it to call our kernel via Int 61 (our kernel
provides a shareable multi-connection TCP as a TSR system service).

James B. VanBokkelen		26 Princess St., Wakefield, MA  01880
FTP Software Inc.		voice: (617) 246-0900  fax: (617) 246-0901