Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!VAX.FTP.COM!wjr
From: wjr@VAX.FTP.COM (Bill Rust)
Newsgroups: comp.protocols.tcp-ip.ibmpc
Subject: Re:  PC-IP ON OS/2 AS PRINTER BRIDGE FROM PC-LAN
Message-ID: <8904271527.AA02245@vax.ftp.com>
Date: 27 Apr 89 15:27:35 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 75


> I have MS LAN-Manager running on a PS/2 model 60 for a couple of weeks
> now, and it served impeccably as a server for PCs running PC-LAN.

> But, like many other sites we have the problem of coexistence with
> TCP/IP.  In fact, the PCs are used almost exclusively for OA functions
> and the REAL production work are done on the UNIX systems.  So, naturally
> they have the clout to buy resources, like expensive Postscript printers
> etc etc.

> I know you can use PCIP to print to the UNIX hosts, but I am thinking
> along another direction: can you intercept LAN-Manager SMB requests and
> redirect them to a LPR target instead?

> The reason is that the SMB redirectors in DOS takes up little memory,
> compared to the exhorbitant amount required for TCP/IP.  This way,
> we can maximize each workstation's available memory.

> Now to the main crust of my question:  Have anyone ported the PCIP
> package to OS/2?  A brief scan of the OS/2 technical info appears
> to indicate this would be trivial since a tasking package is already
> provided in the form of threads.

> Now IF PCIP is available on OS/2 (in source form), and IF I can grab the
> print request SMBs on the server, THEN it should be trivial for me to
> redirect them to a UNIX host using the lpr protocol.

> Can anyone comment on this OR tell me if I am on the right track?
> (I don't want to start coding anything until I know if this is right)


First, let me restate your question so that my comments won't seem
totally out in left field if I haven't understood it. You have a
network of PCs running DOS connected to an OS/2 server. You want to be
able to make requests to the server which then passes them on to a
UNIX host. The server must convert the request from whatever protocol
PC-LAN uses to TCP/IP so that the host can process it properly.

I am not familiar with the SMB redirectors under OS/2, so I can't
comment on how easy it would be to grab them as they come into the
server. But, I have been working on porting a TCP/IP protocol stack
and calling that port trivial may be a bit optimistic.

If you try to do the port, you need several things.  First, you must
make an OS/2 device driver for your protocol stack.  Ray Duncan's
"Advanced OS/2 Programming" is essential if you attempt to do it.
Second, you need a copy of the NDIS spec or else you will need to
write your own device drivers for the various cards out there (as far
as I know there are no public domain OS/2 card device drivers
available). Third, you need the supporting software for binding your
stack to the NDIS driver (the Protocol Manager). I assume that you
already have this.

You have two options in your port of PCIP: put the whole thing in ring
0 or have a small character device in ring zero and put the stack in a
DLL in application space. If you intend to run the thing only on a
server and don't care if the compatibility box has any memory left in
it, then putting the whole thing in ring 0 *may* be better. From my
perspective, the other approach is better.

If you attempt this, you will be venturing into almost uncharted
areas. Much as I hate to say it, signing up for Microsoft Online
is probably a good idea. There are things out there that I know
don't work, things that I would put money on that won't work the
first time you try them, pieces that are missing and other snares
for the unwary. 

I would really like to get some sort of group of people working on
OS/2 networks started so that we each don't have to discover all the
little gotchas. I don't know how to start a group, so if someone who
knows how would email me the information, I would appreciate it.

William J. Rust
FTP Software
wjr@ftp.com