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1991-02-12
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How to set up Concurrent
Connections to Netware and AS/400 servers
via Ethernet
AS/400 - The Ethernet Connection...
-----------------------------------
IBM even surprised it's own personnel on September 28, 1990 when it
actually delivered Feature #2625, an Ethernet adapter for the
AS/400 priced at $4000. After almost two years of vague promises,
IBM was to embrace (I use the term loosely) a network technology
other than the vaunted Token Ring.
However, AS/400 Ethernet required Version 3 of the OS/400 Operating
System which did not begin "formal" shipping until 1991. Early
releases were available before that date. There were many
cautions, but the word "Beta" was never used. In all fairness, a
version received in November was solid.
To access an AS/400 via Ethernet requires PC Support Version 3,
which in turn requires LAN Support Version 1.2 and either 3COM
3C503 or WD Ethercard+ network cards. The AS/400 Ethernet Adapter
offers only an DIX connector; an external transceiver must be
obtained.
Multiple Protocol Stacks for IPX and LANSupport - NDIS vs. ODI
--------------------------------------------------------------
While Gateways and Routers had been the tradition means of
connecting IBM protocols such at IBM 3270 and 5250, the growing use
of TCP/IP on Ethernet was feeding the not unreasonable idea that a
single Ethernet card should be able to more than one protocol.
Some PC's in such multiple protocol (MP) environments actually has
a separate Ethernet card for each protocol - and expensive and
complex solution.
Companies such as Hughes began to offer products such as the
ProLink which allowed the network card hardware to transparently
service several different protocols. The only drawback with the
ProLink was it's expense.
3COM's attempt to address the MP issue resulted in the NDIS
specification. Novell chose not to support NDIS and developed a
totally different specification called ODI. Their premise was that
NDIS did not allow dynamic loading and unloading of protocol
stacks.
3COM responded by publishing a new NDIS specification, and with the
help of IBM and Microsoft persuaded more Ethernet card suppliers to
include NDIS drivers as part of the standard driver library. ODI
drivers appear to be less available than NDIS.
One problem remained for Netware users; the NDIS drivers had
nothing for IPX, and the ODI drivers had nothing for LAN Support on
Ethernet.
3COM 3+ Open Connection for Netware
-----------------------------------
An obscure product to most Novell types, 3+ Open Connection for
Netware is designed to allow 3+ Open users to access Novell file
servers. It contains 3COM's NDIS driver for IPX which may be used
to provide the critical IPX <> NDIS link. I was first alerted to
this by Mike Kouri of 3COM on Netwire, to whom I am eternally
grateful.
Locating this product was no simple matter. As an Integrator, I
wished to purchase the product through distribution rather than via
a 3COM reseller. Both Merisel and Ingram Micro D has difficulty
even identifying the product, let alone being able to deliver.
Fortunately Tech Data had stock. The product is packaged in single
user, 10 user and unlimited (Server) license packs.
Installation
------------
The installation process is totally manual because the supplied
installation program abends when it fails (understandably) to find
the LAN Manager workstation software.
A special IPX.COM file must be created from the .OBJ and .LAN files
supplied in the 3+ Open Connection for Netware. This can not be
done in SHGEN, but must be performed manually using the Novell
utility, NLINK. This NDIS IPX file contains no hardware
parameters, but simply "hooks" to the IPXSTUB driver already
loaded. Although generation is tricky, it only needs to be done
once.
3COM also supplies programs that will allow unloading of IPX in a
manner similar to MARK and RELEASE. They are PRENET and NWUNLOAD.
The latest xxxNETx workstation shells may be unloaded without
external assistance.
Configuration
-------------
Sample CONFIG.SYS and AUTOEXEC.BAT files are provided at the end of
this article. Their operation is described below.
Operation
---------
In CONFIG.SYS, the Protocol Manager (PROTMAN.EXE) reads the NDIS
configuration file (PROTOCOL.INI), loads the specified hardware
driver (ELNKII.DOS for example), a "hook" for IPX (IPXSTUB.DOS) and
then the LAN Support drivers (DXMAMOD0.SYS & DXMEMOD0.SYS). While
all this occurs in CONFIG.SYS, the actual binding of the protocols
takes place by running NETBIND.EXE from AUTOEXEC.BAT.
Once the protocols are bound, the special NDIS IPX.COM is loaded,
followed by the xxxNETx of your choice. After the usual login
procedure, the PCSupport Router, Shared Folders and Workstation
programs may be loaded.
There is no reason why the IPX and xxxNETx have to be loaded before
the PCSupport programs, although that configuration was not
extensively tested.
Memory Considerations
---------------------
As can be imagined, all this takes up quite a bit of memory. The
only way to address this situation is to get some EMS, C&T
ShadowRAM or memory between 640K and 1Mb that can be mapped as
Expanded memory.
Several memory managers are available from Quarterdeck, Qualitas,
Helix etc.. I evaluated Quarterdeck and Helix and ended up using
QEMM/QRAM in over 60 PC's including IBM XT & AT, Compaq Portable,
Portable II, Deskpro, Deskpro 286, 286e, SLT, Packard Bell 286, NEC
386SX.
The only real problem encountered beside the usual struggle for
mappable memory was the refusal of PROTMAN.EXE to be loaded in high
RAM. This is apparently due to the practice of parsing parameters
by scanning the CONFIG.SYS image. Unless these routines are
carefully written, they can be easily confused when they are
themselves parameters of LOADHI type device statements.
AS/400 PCSupport Login
----------------------
Although the PCSupport/LAN Support drivers and configuration files
must be located on the workstation boot device, the test
configuration maintains all other PCSupport files on a Novell
server. If you prefer to access the AS/400 before login to
Netware, all necessary PCSupport files must be locally available.
The PCSupport Router (STRTRTR.EXE) has only one parameter, the name
of the PCSupport configuration file (CONFIG.PCS). When started,
this program requests LAN Support to "open the adapter" and
requests a connection with the specified AS/400 System at a
specified 12 digit Ethernet address. (This address, the AS/400
Ethernet card ID, may need to be bit-reversed; a simple operation.)
On a lighter note, the IBM Token Ring heritage is clearly evident;
the Router program still announces itself as Token Ring Router,
even though it is Ethernet.
The Router will then prompt for a PCSupport Common User ID (CUID)
and password. After entry, the Router will establish a connection
to the AS/400.
If you wish to use PCS Shared Folders, you must run STRTFLDR.EXE at
this point. This program has two parameters specifying the number
of folders (mapped virtual drives) and files.
Many other PCSupport functions are available in Version 3, but the
intention of this article is simply to start a 5250 session. This
is accomplished with WSF.EXE, which has an optional parameter for
a Session Master Profile file. Once loaded, WSF automatically
starts the first 5250 session for you and the login screen will
appear.
The Hot-Key
-----------
Press <ALT><ESC> to return to the DOS session on Netware,
<ALT><ESC> to go back to the 5250 session. The PCSupport Router
and Workstation function use between 50-60K each and may be loaded
in High RAM if available.
Terminating the AS/400 Session...
Once the user has signed off the AS/400, the user must hot-key back
to DOS and stop the WSF session by using STOPWSF. This required a
parameter specifying the Session number which is simply "1" for a
single session. The user will be asked to confirm by pressing
<ENTER> or allowed to return using <ESC>.
Next the PCSupport Router must be stopped by using STOPRTR. If
shared folders are being used, they should be stopped in a similar
manner.
Finally, the memory used by all PCSupport programs may be released
back to DOS by typing RMVPCS ALL.
Conclusion
----------
While 3+ Open Connection for Netware solves the NDIS/IPX problem,
the cost per server is $1995. In many situations, this cost is
small compared to the benefits accrued, but the issue of support
remains vague. 3COM support is targeted at users of 3+ Open rather
than Netware.
This situation is compounded by the recent announcement by 3COM
that it is selling much of it's network software product line
(including this one) to Microsoft.
Sample CONFIG.SYS & AUTOEXEC.BAT files
--------------------------------------
shell=\COMMAND.COM /p /e:512
files=40
buffers=10
device=\QRAM\QRAM.SYS RAM NV
device=\QRAM\LOADHI.SYS /H \PCS\EIMPCS.SYS
device=\LANMAN\PROTMAN.EXE
device=\QRAM\LOADHI.SYS /H \LANMAN\ELNKII.DOS
device=\QRAM\LOADHI.SYS /H \LANMAN\IPXSTUB.DOS
device=\QRAM\LOADHI.SYS /H \LANMAN\DXMA0MOD.SYS 001
device=\QRAM\LOADHI.SYS /H \LANMAN\DXME0MOD.SYS
@echo off
prompt $p$g
set term=MONO
set pctype=IBMAT
PATH=C:\DOS;C:\
\LANMAN\NETBIND
\QRAM\LOADHI /H \NOVELL\IPX
\QRAM\LOADHI /H \NOVELL\NET3
F:
LOGIN
The content of this article is copyrighted material and is made
available courtesy of The Meridian Group, Inc.. Permission is
hereby given to distribute this article providing there is no
alteration of content.