WINDOWS AND TCP/IP FOR INTERNET ACCESS (c) 1995 by Harry M. Kriz
Mr. Kriz has graciously permitted WindoWatch to publish his latest
revision of his timely paper "Windows and TCP/IP for Internet Access".
Release 06 of December 1994.
INTRODUCTION
Internet, the world-wide network of computer networks, has captured the
imagination of the general public. Eighteen months ago, the Internet was
barely mentioned in the popular computing magazines. Now it is the topic
of articles in national news magazines, local newspapers, and
grocery-store tabloids.
Awareness of the Internet has spread primarily by word of mouth. Computer
pundits were not discussing the Internet in Spring 1993 when I first began
investigating the Internet in my work as a librarian. Indeed, most pundits
seem to have acquired Internet access only in the Spring of 1994. Thus,
computer magazines have not been helpful for those wishing to learn about
the Internet.
Now, in December 1994, there is something of a feeding frenzy of interest
in the Internet. Bookstores are flooded with guides to the Internet.
Software vendors are rushing to market with collections of software designed
for navigating the resources on the Internet. It is almost as if the crest
of the Internet wave has passed. Pundits who did not have access to the
Internet last year are already writing negative opinions about the
difficulties of navigating Internet resources, and about the uselessness
of those resources.
Complaints about the Internet are many. Certainly it can be difficult to
find information and resources on the Internet. A great deal of information
is unvalidated, non-authoritative, or otherwise questionable. Some resources
should not be available to children. Some would argue that some of the
information should not be distributed even to adults.
It is important to remember that the Internet is not a service. Rather, it
is a means of gaining access to services and of retrieving information and
other objects that can be represented electronically. In considering
complaints about the Internet, one might draw an analogy between the
Internet and New York City.
New York is big, complicated, and disorganized. The city's myriad
resources can be hard to find. Some of what happens or what is available
in New York should not be seen by children. For those wishing to
navigate the complexity of New York, there are guidebooks, phone
directories, magazine articles, and individuals with expert knowledge
about areas of particular interest. One can navigate the complexity of
the city by subway, taxi, and bus. One can even hire a private guide to
conduct a tour of the city.
The Internet can be compared to the streets of New York City. The services
available on the Internet have their analogies in the city's libraries,
department stores, bookshops, art galleries, street vendors, and street-
corner zealots passing out literature or lecturing the passing crowds. It is
safe to assume that somewhere on the streets of the city there will be found
information and services of interest to almost anyone. However, finding that
information might take some time for someone who is new to the city and its
resources. Similarly, somewhere on the Internet there also will be found
information and services of interest to almost anyone.
Traveling on the Internet requires only a few basic tools. First is a
computer with a network connection to the Internet. A direct connection
using a PC equipped with a network interface card that interfaces with a
local area network linked to the Internet is common at universities, and
becoming more common in businesses. If a direct network connection is not
available, an alternative is to connect to the Internet through the
computer's serial port. This involves a telephone connection to a
terminal server that offers SLIP (Serial Line Internet Protocol) or PPP
(Point to Point Protocol) service. Any of these connections can be used
with a variety of commercial or shareware software to make your personal
computer a host on the Internet and to access services and information
from the entire earth. This paper will emphasize the use of freeware and
shareware versions of software running under Microsoft Windows.
INTERNET SERVICES
The Internet services of interest to most people consist of four basic
functions. These are electronic mail (e-mail), Internet news, file transfer
between computers (FTP), and remote login to another computer (telnet).
Access systems like Gopher and World Wide Web now supplement these basic
Internet functions by assisting the user in searching for and retrieving
relevant information in a user-friendly manner.
Until recently, Internet functions were accessible primarily through
character-based interfaces using a variety of complex command sets.
Thus, until recently, best-selling books on the Internet contained page
after page of screen displays or command sequences captured from UNIX-based
systems executing basic Internet functions.
Affordable Internet software for Windows first became available in Spring
1993. Prior to that time, Windows users were dependent for Internet access
on expensive, proprietary, commercial products in which each vendor's
offerings were mutually incompatible with every other vendor's
offerings. Publication of the Winsock applications programming interface
provided a way for individual client software (such as a telnet or FTP
client) to be compatible with every vendor's networking products. As a
result, beginning in 1993 there was a blossoming of freeware, shareware,
and commercial Internet software for Windows.
Of special interest has been the development of Windows interfaces to the
World Wide Web. Mosaic is the best known Web browser. Other choices include
Cello, Netscape, and WinWeb. The Web was developed by the high energy
physics community to distribute technical papers and other forms of data.
WWW is now widely viewed as a means for educators, businesses, and hobbyists
to distribute multimedia information to a world-wide audience. Graphical
WWW clients enable publication of data over the Internet in a manner
which allows the user to view text, color graphics, sound, and video in
a manner that approaches the usability, and surpasses the functionality,
of a printed magazine. Those interested in publishing WWW documents may
find it useful to read my paper "Teaching and Publishing in the World
Wide Web." A plain text version is available by anonymous FTP from:
nebula.lib.vt.edu in directory /pub/www under the name websrv01.asc.
A hypertext version is available through the Web at
http:/learning.lib.vt.edu/webserv/webserv.html.
E-MAIL
Electronic mail is probably the most widely used Internet function. A
commonly used configuration requires that a user have an account on a
POP (Post Office Protocol) mail server. The e-mail client software
accesses the server and downloads any incoming messages to the user's
PC. Mail composed at the user's PC is transmitted to the Internet
through the mail server.
INTERNET NEWS
Internet news, also referred to as USENET news, is a conferencing
system made up of thousands of topical conferences known as news
groups. Those familiar with electronic bulletin board systems will
compare Internet news to echo conferences. Others will draw an analogy
to mailing lists such as listserv on BITNET. The user reads the news by
using client software to subscribe to a selection of news groups. When
the client software accesses an NNTP (Network News Transfer Protocol)
server, the server downloads to the client a list of subjects for all
unread messages stored on the server for the selected news group. The
user can then select any message for reading, post a response to the
message to the group, or reply directly to the original poster of the
message. The client software maintains on the user's PC a list of all
available groups on the server, along with records of which messages
have been read or skipped over. Only the messages selected for reading
are actually downloaded to the user' PC.
FTP
FTP (File Transfer Protocol) allows the transfer of files between any
two computers of any type. Files can be transferred from PC to PC, PC
to mainframe, PC to Mac, PC to UNIX machine, and vice versa. Any kind
of computer file, whether it be a text file or a binary file
representing software, graphics images, or sounds, can be transferred.
Of course, whether the file is usable on the receiving machine depends
on the nature of the file and the availability of software to make use
of the file.
TELNET
Telnet enables the user of a PC to login to a host computer at another
site on the Internet. The user's PC then acts as a dumb terminal
attached to the remote host. Such access usually requires that the user
have an account on the remote host. For instance, a student or faculty
member at one university might have an account on a computer located at
another university. An increasing number of commercial services are
becoming available via telnet, including services such as the Dow Jones
News Service and the Lexis/Nexis service. In addition, some services
are available without charge. For example, hundreds of libraries in all
parts of the world allow free remote access to their computerized
catalogs and to some specialized databases.
GOPHER
Gopher is a system that enables the user to find files and other
Internet services by navigating a system of text menus and submenus. As
a corollary, it provides a means for information providers to publish
information on the Internet in a discoverable manner. Prior to the
development of Gopher at the University of Minnesota, information on
the Internet was located by asking friends and strangers where to look.
The first step in using a Gopher client is to "point" the client at the
address of a known Gopher server. The client then retrieves that
Gopher's menu of topics. Typically, many of the topics on a Gopher menu
are pointers to yet other menu items on other Gopher servers. The fact
that items in the sequence of selections might come from different
Gopher servers in widely scattered parts of the world is transparent to
the user. The Gopher client software presents the many different Gopher
servers as if they represented a single application on a single
machine. Navigating such menus can lead the user to skip from one
Gopher server to another, literally retrieving information from servers
scattered around the world in just a few minutes.
Items on Gopher menus can be of many different data types in addition
to menus listing choices of topics. When an item such as a text,
graphics, or sound file is selected, the Gopher client transfers the
file to the user's PC. Then, as an option, it may load the file into an
appropriate "viewer" selected by the user. A simple text file could be
loaded into Windows Notepad. A graphics file in GIF or JPEG format
might be loaded into LVIEW, a popular freeware graphics viewer for
Windows. A binary program file would simply be downloaded into a
designated directory for use at some other time. Finding relevant
Gopher menu items is facilitated through the use of Veronica, which is
a database of the text of Gopher menus. Most Gopher servers will
include Veronica access as a menu selection.
WORLD WIDE WEB
World Wide Web (WWW) is a system that enables users to find and
retrieve information by navigating a system of hypertext documents. In
a hypertext document, selecting a highlighted word or phrase causes a
new document to be retrieved and displayed. Thus, WWW leads the user to
skip from one document to another, retrieving information from servers
scattered around the world.
Viewing a WWW document with a Windows graphical client such as Cello,
Mosaic, Netscape, or WinWeb is similar to reading a magazine.
Information is displayed with typographic fonts and color graphics.
Unlike a magazine, the static display can be supplemented by sound and
video clips that are played by clicking an icon embedded in the
document. Clicking on a highlighted word or phrase in the document may
cause the reader to skip to another part of the displayed document, or
it may cause yet another document to be retrieved.
TECHNICAL DETAILS
It is helpful to know some Internet terminology when working with your
local network specialist or Internet service provider to make your PC a
host on the Internet. The two common modes of Internet access are
through a direct network connection or through a serial connection to a
SLIP or PPP server.
A direct network connection involves installing a network interface
card (NIC) in your PC. Most likely this will be an ethernet card. This
card in turn is connected to your organization's local area network.
Wiring usually consists of coaxial cable (as in thin-wire ethernet) or
twisted pair telephone wiring (as in 10Base-T ethernet). The local
network in turn must be connected to the Internet, and it must be
capable of handling TCP/IP data packets.
TCP/IP (Transmission Control Protocol/Internet Protocol) is the method
by which data on the Internet is divided into packets of bytes. Each
packet is delimited with header information that includes the
destination address where the packet is to be routed when it is
transmitted over the Internet. The local network and your PC may also
be using other network protocols simultaneously with TCP/IP. For
instance, your PC may already be connected to a network using Novell,
LANtastic, or Windows for Workgroups network protocols.
SOFTWARE LAYERS
Several layers of software are involved in implementing a direct
network connection. A commonly used method is to first install a piece
of software called a packet driver that deals directly with the network
interface card. This is loaded under DOS from the AUTOEXEC.BAT file as
a TSR (terminate and stay resident) program. A packet driver should be
included with the software that comes with the card. If the
manufacturer of the card does not supply a packet driver, free packet
drivers are available in the Crynwr Packet Driver Collection as
described at the end of this document.
The next layer of software is the TCP/IP driver, which can be
implemented in a variety of ways. Until recently, this was often
another DOS TSR program loaded from the AUTOEXEC.BAT file. Increasingly
this layer of software is implemented as a Windows dynamic link library
(DLL) or virtual device driver (VxD). The DLL and VxD implementations
do not require any modification of the boot files on the PC.
The TCP/IP driver that implements TCP/IP functionality for the system
is referred to as the TCP/IP protocol stack. The driver may be written
to work with a specific network card, or it may be written to interface
with a packet driver. In the latter case, a single TCP/IP driver can be
used with any network card for which an associated packet driver is
available. Thus, the packet driver specification eliminates the need
for software vendors to customize their TCP/IP protocol stack for every
network card with which it is used. When using a packet driver with
Windows applications, another DOS TSR referred to as a virtual packet
driver may be required to interface between the Windows-based TCP/IP
protocol stack and the DOS-based packet driver.
When a direct network connection is not available, Internet TCP/IP
software can be used over serial lines to connect to a SLIP (Serial
Line Internet Protocol) or PPP (Point to Point Protocol) server that
provides a connection to the Internet. SLIP and PPP do not require the
software drivers that are necessary with a direct network connection.
The Trumpet Winsock shareware package to be described later has all
SLIP and PPP functions included in the TCP/IP driver, which is
configured through a Windows dialog box.
SLIP and PPP are less transparent to the user than a direct network
connection. The user first obtains an account on a SLIP or PPP server.
Connecting to the Internet involves dialing the server using normal
serial communications software and establishing a SLIP or PPP session.
Once the session is established, TCP/IP software running on the PC can
be used just as if the PC was connected directly to the Internet
through a network card. SLIP and PPP users are well advised to settle
for nothing less than transmission at 14,400 bits per second. World
Wide Web especially transmits a great deal of data when images or sound
are involved. Slow modems and slow connections will discourage anyone
but the most dedicated user from exploring the possibilities of the
Internet.
TCP/IP client applications work at the top of the layers of software so far described. Client software runs independently of the type of connection to the Internet. TCP/IP applications frequently are referred to as clients because they access a corresponding server (a daemon in UNIX terminology) on another machine. An FTP client, for instance, is the application on the user's machine that accesses the FTP server running on a host computer located elsewhere on the Internet.
Until recently, each TCP/IP client had to be written to interface with
a particular vendor's TCP/IP protocol stack. Clients that worked with
one vendor's TCP/IP driver would not work with a driver from another
vendor. This restriction was eliminated with the development of the
Windows Sockets Application Programming Interface, otherwise known as
the Winsock API, or more simply Winsock. Winsock works in the layer
between the TCP/IP client and the TCP/IP protocol stack.
WINSOCK
"Winsock" is the buzzword that dominates discussion about TCP/IP and
Windows. All of the software to be described here is based on Winsock.
The implementation of Winsock is transparent to the user, but it is
helpful for the end-user to know how it supports Windows applications.
Winsock (short for Windows sockets) is a technical specification that
defines a standard interface between a Windows TCP/IP client
application (such as an FTP client or a Gopher client) and the
underlying TCP/IP protocol stack. The nomenclature is based on the
Sockets applications programming interface model used in Berkeley UNIX
for communications between programs.
When you launch a Winsock compliant client like WSGopher, it calls
procedures from the WINSOCK.DLL dynamic link library. These procedures
in turn invoke procedures in the drivers supplied with the TCP/IP
protocol stack. As described earlier, the TCP/IP driver communicates
with the computer's ethernet card through the packet driver.
The WINSOCK.DLL file is not a generic file that can be used on any
system. Each vendor of a TCP/IP protocol stack supplies a proprietary
WINSOCK.DLL that works only with that vendor's TCP/IP stack.
The advantage of Winsock to the developer of a client is that the
application will work with any vendor's Winsock implementation. Thus,
the developer of an application such as a Gopher client has to
understand the Winsock interface, but he does not have to know the
details of each vendor's TCP/IP protocol stack in order to make his
client application compatible with that stack. Winsock also eliminates
the need for an application developer to include a custom TCP/IP
protocol stack within the application program itself. This was a common
means of implementing TCP/IP clients under DOS, and some early Windows
TCP/IP clients also used this method. The use of protocol stacks
internal to the client results in conflicts when two clients try to
access the single packet driver that is communicating with the network
card. The ability to create applications compatible with any vendor's
Winsock compliant protocol stack resulted in a blossoming of Winsock
compliant shareware applications beginning in Summer 1993.
The Winsock standard also offers advantages to the end-user. One advantage is that several Winsock applications from different vendors can be used simultaneously. This is a marked improvement over earlier packet driver applications in which each application contained a built-in TCP/IP stack. Such applications cannot share the packet driver except through the added complexity of a packet multiplexer such as PKTMUX. A second advantage to the user is that any Winsock compliant application will run with any vendor's TCP/IP protocol stack and accompanying WINSOCK.DLL.
Unfortunately, some commercial vendors of TCP/IP clients are not yet
taking advantage of Winsock capabilities. There are still TCP/IP
clients that require dedicated access to the packet driver, and there
are clients that will run only with the TCP/IP protocol stack supplied
by one particular vendor. Fortunately, the trend is for all commercial
vendors to make their applications more usable and portable through the
use of the Winsock standard.
SOFTWARE DESCRIPTIONS
Once the required networking hardware is installed and an IP address is
assigned, or once an account is obtained on a SLIP or PPP server, the
user needs to install a TCP/IP protocol stack and a selection of TCP/IP
clients. The remainder of this paper describes such software.
For each application, I briefly outline the installation procedures. I
do this primarily to illustrate the simplicity of using Windows for
Internet access. Please be sure to read any text files included with
each package in order to complete the configuration and to learn about
all functions of the software.
I have installed all the software described here for many of my
colleagues in the Virginia Tech Libraries. With some practice I have
found that I can install a complete suite of TCP/IP applications in
about half an hour. Some individuals who read the previous versions of
this document were up and running in less than an hour after obtaining
the software. They expressed their delight at the ease of networking
with Windows.
Editorial Note! The balance of this excellent paper gives details to
configure a system to access the Internet. Because of the length we
have reduced font size but recommend that you copy to another sheet
that which is useful to you and enlargefor better readability!
DISCLAIMERS AND LIMITED WARRANTIES
I am not an expert on anything. I am just an enthusiastic end-user of
these products in my daily work. I have used all of the client software
with a direct connection to an ethernet network using a Western Digital
or SMC ethernet card with the Trumpet Winsock shareware TCP/IP protocol
stack and WINSOCK.DLL. In addition, I have used most of the clients
with FTP Software's commercial package PC/TCP version 2.2.
In the latter case I obtained the most recent version of FTP Software's
WINSOCK.DLL file by anonymous FTP from ftp.ftp.com in directory
/support/ftpsoft/winsock under the name winsock.exe (a self-extracting
ZIP file)(November 16, 1994 | 46,375 bytes).
The Trumpet and FTP products both use a packet driver interface to the
network card. I have also used most of the clients on a Windows for
Workgroups network using Microsoft's add-on TCP/IP package. This
package is available by anonymous FTP from ftp.microsoft.com in the
directory /peropsys/windows/public/tcpip under the filename WFWT32.EXE
(November 29, 1994 | 680,621 bytes), a self-extracting archive file. I
also have used most of the client software through a SLIP server using
the Trumpet Winsock. Both a dialup connection to the SLIP server and a
modemless connection through an IBM/ROLM digital switch were used at
various times.
I have no experience with PPP connections.
As discussed above, the client software described here should run with
any TCP/IP protocol stack that offers Winsock support. If your PC is
already using a network operating system that does not include Winsock
support, you should check with your vendor to find out if Winsock
support is available. If Winsock support is not available from your
vendor, then it may be possible to install the Trumpet Winsock TCP/IP
protocol stack over your existing network drivers using a small program
known as a packet driver shim. Instructions for this configuration are
included in the Trumpet Winsock documentation.
In the following descriptions, information about version numbers, file
sizes, and dates was verified on December 20, 1994.
TRUMPET WINSOCK (TCP/IP protocol stack and basic clients, ) (including
telnet, ping, and Archie )
*Comment: You need this package (or some other TCP/IP protocol stack
that supports Winsock) before you can use any of the client software
described later. Trumpet Winsock does not require any additional network
software. Its TCP/IP functions can be installed over other network
software such as Novell or Windows for Workgroups using a packet driver
shim. Instructions for such installations are included in the ZIP file.
Author: Peter Tattam, Trumpet Software International
(December 20, 1994 | 2,240,650 bytes) Available by anonymous FTP from:
ftp.ncsa.uiuc.edu in directory /Web/Mosaic/Windows Installation: 1.)
Copy W32SOLE.EXE to a temporary directory and execute the program. This
will extract the two component files INSTALL.BAT and WIN32DSK.EXE. The
latter is another self extracting archive file.
2.) Execute INSTALL.BAT.
(This batch file issues the command
WIN32DSK.EXE -d
to extract the component files into the subdirectories DISK1, DISK2,
and DISK3. These subdirectories will be created below the temporary
directory containing INSTALL.BAT.)
3.) Change to the DISK1 subdirectory
and execute SETUP.EXE. This will install Win32s version 1.20 with OLE.
Many of the files will be installed in the directory
C:\WINDOWS\SYSTEM\WIN32S. If you have an older version of WIN32S already
installed, it will be removed. You shouldallow installation of the game
FreeCell in order to test that Win32s is properly installed on your machine. Once this is verified, you can erase the files and directories in the temporary installation directory.
4.) Copy MOS20A8.EXE to the temporary installation directory. Remember to erase any files and subdirectories left in the temporary directory from the installation of Win32s.
5.) Execute MOS20A8.EXE to extract the component files, including SETUP.EXE.
6.) Execute SETUP.EXE to install Mosaic version 2.0 alpha 8 in
the directory of your choice. MOSAIC.INI will be copied to the
C:\WINDOWS directory.
7.) Launch the program. Read the files README.WRI
and RELNOTES.HTM to learn how to fully configure Mosaic to your needs.
8.) When installation is complete, you can remove the temporary
installation directory.
NOTE: You can avoid the added complexity of installing Win32s and the
substantial demands it places on your PC by using the older Mosaic
It remains true that the best guide to the Internet is the Internet itself. The best software for navigating the Internet is freely available on the Internet.
Considerable information about the Winsock API, along with some application programs, is available by anonymous FTP at sunsite.unc.edu in directory /pub/micro/pc-stuff/ms-windows/winsock.
The anonymous FTP sites that I list throughout this paper as sources for programs are the sites designated by the software authors as their home sites. These sites will always have the latest version of the software.
In addition, copies of the software may usually be obtained by anonymous FTP from CICA (Center for Innovative Computer Applications) at ftp.cica.indiana.edu in directory /pub/pc/win3/winsock. Files are also available from this same address using a Gopher client. Gopher access is preferable because the CICA FTP server is the main Internet site for Windows applications. It is usually busy, and you may have difficulty establishing an FTP connection.
It is the case that the collection at CICA will NOT always contain the latest version of software, even if a newer version has been uploaded to CICA by the author. CICA does not allow anonymous users to view or download program files from the uploads directory, where the newest version might still be in the holding pattern. Also, the versions at CICA may not have the same file dates as those at the home sites.
There is a listserv that provides a daily listing of new uploads to
CICA. Included in the mailing are the content of any text files
accompanying those uploads and a list of files that have been moved from
the uploads directory to the public directories so as to be available
for downloading. You can subscribe to CICAL by sending e-mail with no
subject and the message sub CICA-L Your Name to
listserv@ubvm.cc.buffalo.edu.
There are several other Internet sites that provide mirror copies of the
windows collection at CICA. These are listed in the message displayed if
you are denied access to CICA. The list of mirror sites also is included in
the file README in CICA's directory /pub/pc/win3. These mirrors can be just
as busy as CICA. As an example, the mirror at polecat.law.indiana.edu was
recently removed due to overload on the server. When using CICA, it is
helpful to download the file INDEX (ascii, about 285,000 bytes) or INDEX.ZIP
(about 122,000 bytes) from the directory /pub/pc/win3. INDEX contains
one-line descriptions of each file in the collection. The news groups
alt.winsock, and comp.protocols.tcp-ip.ibmpc carry discussions of the
Winsock specification and Winsock compliant applications, as do the
groups in the comp.os.ms-windows.networking hierarchy. Trumpet Winsock
and related clients are discussed in several news groups in the trumpet
hierarchy. Information about specific clients may be found in groups
devoted to that class of client.
For instance, WSGopher is discussed in alt.gopher and in
comp.infosystems.gopher. Cello, Mosaic, Netscape, and WinWeb are discussed
in the sections of the comp.infosystems.www hierarchy.
The BITNET listserv WIN3-L@UICVM carries discussions about all topics
relating to Windows, including Winsock applications. Some news servers carry
this listserv under the news group name bit.listserv.win3-l.
A comprehensive list of FTP'able Winsock applications is available from
Larsen Consulting and Sales, Phoenix, Arizona, USA. To get a copy of the list,
send an e-mail message to info@lcs.com with the Subject: FAQ. Nothing else
should be in the message. The list is also available on the World Wide Web
at http://www.lcs.com/.
Frequently Asked Questions about TCP/IP on PC-compatible computers are
answered in a FAQ written by Bernard D. Adoba. The text is posted monthly
on the news group comp.protocols.tcp-ip.ibmpc. A copy of the newsgroup
posting is available as three separate files from rtfm.mit.edu in the
directory /pub/usenet-by-hierarchy/comp/protocols/tcp-ip/ibmpc. The
complete text of the files dated November 3, 1994 contains over 214,000
bytes. The filenames are decidedly non-DOS, so you will want to assign
filenames if you download from this source. The FAQ is also available as a
single ZIP file named ibmtcp.zip (79,454 bytes | October 29, 1994) from
ftp.netcom.com in the directory /pub/mailcom/IBMTCP. Each of these sites
can be troublesome. They frequently are busy or unresponsive to
commands.
Finally, the FAQ, and other publications about Internet software for the PC,
can be accessed on the World Wide Web page maintained by Bernard Adoba. The
page entitled "Internaut: The PC-Internet Connection Update Page" is located
at http://www.zilker.net/users/internaut/update.html. The Crynwr packet
drivers collection is available by anonymous FTP in the well-known
Simtel20 collection, as well as through a variety of other methods. The
primary publicly available site for Simtel20 files is at
oak.oakland.edu. The packet drivers are in directory
