🚀 go-pugleaf

1. What are they?

A packet driver is a terminate-and-stay-resident program for PCs
running MS-DOS.  Packet drivers hide the differences between network
adapter, and they permit multiple protocol stacks to access the same
network adapter at the same time.  They also make it easier to
install new networking software because the driver is already
installed and working.

On a more technical note, they allow programs to send packets,
receive packets, and determine the adapter's address.  Packet
drivers, by themselves, do not provide any application-level
services.  Some application is needed which will make use of the
low-level packet driver services.

2. What happens without a packet driver?

Without a packet driver, network software must access the adapter
directly. Every adapter is different, so the network software must be
programmed for each adapter.  And because each program is writing to
adapter memory, setting I/O ports, handling interrupts, etc.,
unfriendly programs do not work together.

When you use a packet driver, it handles the details, not the network
software. It doesn't matter if an adapter is I/O mapped, memory
mapped, or bus mastering. In addition, because only one program is
accessing the adapter, multiple protocol stacks can gain access
through the packet driver.

3. What don't they do?

They don't hide the difference between network technologies.  An
ARCNET driver needs ARCNET support, an Appletalk driver needs
Appletalk support, etc.  Having just said that, some packet drivers
emulate Ethernet, e.g. IBMTOKEN, ARCETHER, ETHERSLIP.

They also don't let you run multiple identical protocol stacks.  That
means that you can't run two TCP/IP stacks at the same time, e.g.
NCSA Telnet and PC-NFS.  Each program has its own TCP/IP stack, and
each expects to receive IP and ARP packets. Even if the packet driver
was modified to deliver the packets to both stacks, you still have
the problem of determining which stack should reply to which packets.

4. Where do they come from?

The Packet Driver Specification (PDS) was written by FTP Software.
Some companies have written their own packet drivers.  The majority
of packet drivers were written by individuals, and have been
collected by Russell Nelson while he was at Clarkson University. This
collection used to be called the Clarkson Packet Driver Collection.
Clarkson is now completely disassociated with any packet driver
collection, so the collection is now called the Crynwr Packet Driver
Collection.

5. What do they work with?

There are many applications that use the packet drivers, too many to
list here. Any such list would be incomplete because new applications
are constantly being written.  Therefore, we will name the most
popular and list the rest in the collection's SUPPORT.DOC file.

Freely copyable software:

NCSA Telnet -- NCSA's Telnet.  Provides VT-100 terminal emulation.
KA9Q aka NOS aka NET -- Phil Karn's complete TCP/IP package.  Free to
	some users.
Trumpet -- Usenet news reader using NNTP.
WNQVTNET -- Windows Telnet, FTP, news reader.  Shareware.
BYU and Intel have free packet driver clients for NetWare's IPX.

Commercial software:

TCP/IP -- FTP Software, The Wollongong Group, Beame & Whiteside,
	SunConnect, James River Group.  Only a very few TCP/IP stacks
	do not support packet drivers.
NetWare -- BYU and Intel have free packet driver clients for NetWare's IPX.
Monitors -- FTP Software, Intel, Klos Technologies, US Networx, General S'ware
Others -- Performance Technology, WEBos, Invisible LAN, LANsoft and Banyan.

6. Support?

The packet drivers in the Crynwr collection are freed software.  They
are available from many places for the cost of copying them.
However, they do not come with support unless purchased directly from
Crynwr Software.

We accept purchase orders and checks drawn in US funds via mail, FAX,
and telephone.  Terms of the support are available on request.

7. How do I get them?

Crynwr Software distributes supported drivers only.  You can get
unsupported drivers from the following locations.

Mail:

Columbia University distributes packet drivers on PC diskette by
postal mail.  Please call (212) 854-3703 for ordering information, or
write to: Kermit Distribution, Dept PD;  Columbia University Center
for Computing Activities;  612 West 115th Street;  New York, NY
10025 or send e-mail to kermit@watsun.cc.columbia.edu (Internet) or
KERMIT@CUVMA (BITNET/EARN).

FTP/email:

The packet driver collection has its own directory devoted to it,
pd1:<msdos.pktdrvr>.  The drivers are there, along with many free
programs that use the packet drivers.

SIMTEL20 files are also available from mirror sites OAK.Oakland.Edu,
wuarchive.wustl.edu, ftp.uu.net, nic.funet.fi, src.doc.ic.ac.uk or
archie.au, or by e-mail through the BITNET/EARN file servers.

Modem:

If you cannot access them via FTP or e-mail, the packet drivers are
also available for downloading from Detroit Download Central (313)
885-3956.  This is a subscription system with an average hourly cost
of 17 cents.  It is also accessible on Telenet via PC Pursuit and on
Tymnet via StarLink outdial.

8. What about the Novell/Unix connection?

There is no problem transporting both Novell (actually, NetWare) and
Unix (actually, TCP/IP) packets over the same network at the same
time.  NetWare packets have one magic number, TCP/IP another.  The
trick, for DOS users, is to run both at the same time on the same PC.

NetWare servers and clients can be configured for standard Ethernet
II packets, or left alone for nonstandard NetWare packets.  This
configuration process is done by a program called econfig.

NetWare's drivers access the adapter directly, which will cut off
packet driver access to the adapter. The way to convince NetWare to
avoid stomping on your packet driver is to use a version of IPX that
accesses the adapter through a packet driver.  There are two such
IPXes, both of them freely copyable. Brigham Young University (BYU)
wrote one back in April of 1989. Intel wrote one more recently, and
is continuing to modify it as needed.

With BYU PDIPX, you must either econfig or use the packet driver's -n
switch. In any case, BYU requires that you econfig the client. The
Intel PDIPX lets you choose to econfig your network or not.

9. Are there alternatives to packet drivers?

After the packet driver specification had been published, Microsoft
and Novell devised their own driver specifications, NDIS and ODI (aka
ODLI).  LAN Manager requires an NDIS driver, and newer versions of
NetWare require an ODI driver. The specifications for NDIS drivers
are freely copyable, but writing an ODI driver requires a
multi-thousand dollar toolkit from Novell.

There are several "shims" that convert one specification into the
other: dis_pkt, which emulates a packet driver using an NDIS driver,
odipkt, which is a packet driver over ODI, and pdether, which is an
ODI driver over packet driver.  Crynwr Software distributes these,
although we do not support them.

-russ <nelson@crynwr.com> What canst *thou* say?
Crynwr Software           Crynwr Software sells packet driver support.
11 Grant St.              315-268-1925 Voice  |  LPF member - ask me about
Potsdam, NY 13676         315-268-9201 FAX    |  the harm software patents do.