From: garyrich@qdeck.com (Gary Rich)
Newsgroups: comp.os.msdos.desqview
Subject: Re: dv/x on packet driver
Date: 9 Nov 92 18:53:46 GMT
Organization: Quarterdeck Office Systems, Santa Monica CA

In article <1992Nov6.132539.25@elmrd6.ineab.ikea.se> anos@elmrd6.ineab.ikea.se writes:
>>>
>>>I hv got dv/x without network manager, is it possible to get dv/x to
>>>work with a packet driver? I hv a WD8003e card and the packet driver.
>> 
>> You've got to have more than just a packet driver.  We don't talk to anything
>> at the packet interface level.  We need a network protocol like TCP/IP or
>> IPXSPX or NETBIOS to talk to.  If you have a supported instance of one of 
>> these protocols loaded, we don't know or care of it is packet driver or
>> ODI or NDIS or whatever underneath.
>> 
>> Gary Rich 	<support@qdeck.com>
>> 
>
>Gary, could you please explain a little more on this. I'm sure there is a
>large interest around the globe among DVX users on this subject. Include 
>real info as product names, functional requirements etc.
>
>Thanx in advance
>
>/Anders

Ok.  I'll try to make this short and painless without drifting too far
from the truth.  There are many books available on the subject if it's
still too vague or confusing.

The OSI model:

OSI is a universal model that was designed by ISO to describe the framework 
for the the way information goes across a network.  It splits this up into
"layers" to define what goes on where.  The layers are:

layer 1:	Physical

The hardware/electrical level of whats going on, such as thinnet and a 
WD 8003 network card .

Layer 2:	Data Link

The host to host delivery layer.  It assembles data into frames and transmits 
it.  It also does some low level error checking.  Ethernet and Token ring
sit at this layer.  So does a Clarkson/Crynwyr Packet driver. 

 A packet
driver provides a "shareable interface" to ethernet or Token Ring or Slip
or whatever.  It allows multiple transport/network layers to talk to the
network card without crashing into each other.  Any app sitting above the
packet driver can get access to the layer 2 functions by callin the interrupt
that the packet driver is on (usually 60h).  This isolates the internals
of operating the network card.  The packet driver is the only thing that needs
to know what kind of network card you have or what IRQ# it's on, etc.

Layer 3:	Network

Gets data from layer 2 and routes it to the appropriate protocol address.
The IP part of TCP/IP sits at this layer.  Note:  The Internet is an IP
based network.

Layer 4:	Transport

Provides reliable user to user communication and error checking.  This layer is
largely what takes care of transmission reliability.  The TCP and UDP parts
of TCP/IP sits at this level.  Novell's IPX also sits largely at this layer.

Layer 5:	Session

Provides connection services, such as establishing and maintaining a session.
Netbios sits at this layer.  So do our Network managers and DVX's Socket 
interface.  As you can see this is the problem with you just having a packet
driver.  You have layers 1 & 2.  We also need layers 3 & 4.

Layer 6:	Presentation

Controls the way data is represented to the computer, such as DOS or UNIX.
Programs like telnet & ftp and X applications sit at this layer and the 
one above.

Layer 7:	Application

Programs like mail, Xroach, Smoking Clover, and other usefull things.

=====================================================

You can clearly see where you are missing a piece of the pie here.  Having
Quarterdeck write our own Layer 3 & 4 is like having us write a whole
new network operating system.  Not impossible, but one whale of a programming 
job.

Here's a list of what we support @ layer 3/4 that itself also supports a packet
driver @ layer 2:

PCTCP Version 2.05pl3 and higher
Beame & Whiteside BW-NFS		(currently in beta)
Wollongong Pathway			(currently in beta)
Sun PC-NFS				(currently in beta)

PC/IP, NCSA Telnet, KA9Q, and CUTCP also support packet drivers, but we don't
currently have support for them.

I cribbed a lot of the above from FTP Software's PC/TCP Ineroperablility 
Guide.  It's worth grabbing a copy of to get your feet wet.  The true power
propellor head will go straight to Tannenbaum.

Gary Rich		<support@qdeck.com>