SUMMARY: Appletalk printing again

From: Lisa Weihl (lweihl@cs.bgsu.edu)
Date: Thu Nov 20 1997 - 17:54:53 CST


Sorry it's taken me so long to post this summary. I'd like to thank Mark
Bergman for taking the time to send me the very detailed explanation of the
situation that I have included below. I was understanding properly, I just
needed a few pieces to fit. It's just easy to get confused when trying to
sort it all out because people tend to say Appletalk(network? layer) when
they mean LocalTalk(physical layer).

Original Problem: would like to get rid of Gator Box if possible. Used for Macs
                to print to Localtalk printers and for Unix to print to
                Appletalk printers.

Solution: Gator Box can go only if....

1. Unix side needs something to make the printing appletalk compatible (cap
or netatalk for freeware)or the printer needs to be able to understand bsd
printing(like a LaserWriter 16/600 PS can) and we need postscript filters
since we are letting the GatorBox do that now.

2. Still need some kind of converter to hang off the back of the LocalTalk
printers to convert Ethertalk to Localtalk. These adapters can be
purchased at around $250/printer. Or if you have several printers in one
location they have ones for around $300 that will do several localtalk
devices.

Personally, it I have tabled this matter since we may be able to just trade
away the LocalTalk printers to other areas on campus for Ethertalk ones.

I will include Mark's whole reply to my message as he added his comments
interspersed with mine and it'll refresh the original problem.

=> The problem is the old problem of printing from Unix to Appletalk printers.
=>
=> MAIN CONCERN-- We'd like to get rid of our GatorBox if possible.

What's the problem with it?

=>
=> Here is an outline of my current situation:
=>
=> 10BaseT Ethernet network consisting mostly of Macs, 4 Unix servers, 2 of
=> which are login machines for users and about 6 Sun LX Workstations. Shortly
=> to add 2 NT Workstations to this configuration with a possible replacement
=> of some Macs by NT Workstations by Sept. 98.

Sounds similar...
=>
=> As standalone nodes on the network:
=> 3 Ethernet printers (2 Apple LW 16/600PS, 1 HP5si)
                                                   ^^^^^
                                                The HP5si mx(?), right?
                                                Does the printer have
                                                the AppleTalk language
                                                option enabled?

=> 5 Appletalk printers (LaserWriter NTX and LaserWriter IIg)
     ^^^^^^^^^
        Are these printers on Ethernet or LocalTalk?

Sounds similar...
=>
=> Problem #1 - printing text and postscript files from my Unix boxes.
=> Currently all print jobs spool to a SunOS4.1.3_U1 machine (which I want to
=> upgrade to Solaris within a year) and it passes the files to a Cayman
=> GatorBox to do 2 things 1) Text to Postscript conversion 2) printing to the
=> appletalk printers from Unix hosts (no spooling from Macs)
=>
=> Questions:
=>
=> Question #1 - I realize item 1 above can be taken care of with filters. Can
=> I get these filters at some ftp site? I also there are some in netatalk.

The printing filters are part of the lp/lpr packages with Solaris (I
don't remember about SunOS). You could install LPRNG (a free, bsd-ish
lpr packages) and get the filters that way. I think that "enscript"
is a free text to PostScript encapsulation filter.

=>
=> Question #2 - I've seen all the archives on CAP and netatalk. I'm trying

We run CAP.

=> to install netatalk. Actually on a Solaris machine in my office that I use
=> for testing things. I have all the daemons installed and running. I'm
=> having a bit of trouble configuring. Can anyone tell me exactly what files

Personally, I find CAP's configuration to be quite confusing.

=> I should be changing? And do I have to HUP a daemon. I'm a little confused
=> on if I should change /etc/printcap or .../atalk/etc/papd.conf since I
As to which daemons/files to change, it depends on what you want to change...

        Unix only printing (print filters), change /etc/printcap

        Definitions of printers (names, adding deleting, etc.),
        change things within CAP.

=> don't need to spool from Macs. I only need to get items printed from Unix
=> into appletalk form.
=>
=>
=> Question #3 - Mac printing is not spooled but must pass through our Cayman
=> Gatorbox to print to Appletalk printers. Here's my first question, are
=> things passing through there because they need to convert from Ethertalk to
=> Localtalk? Is this a conversion that would have to be done on the Unix side
Whoa! You mention Localtalk, but your earlier description was of a
10BaseT ethernet. LocalTalk is Apple's old network technology. It uses
twisted pair (telephone) wiring at 230Kb/s, and is a "flat" network
topology (until you start adding things like StarNet controllers,
GatorBox/FastPath bridges, etc.). The AppleTalk protocol running on
Ethernet wiring is called Ethertalk (though the term isn't widely
used).

You've got both protocol (tcp/ip ==> AppleTalk) and physical
layer (10Mb/s Ethernet ==> 230Kb/s LocalTalk) conversion going on. The
CAP (or netatalk software) can do the protocol translation. If all
your AppleTalk printers are on Ethernet, you don't need the GatorBox at
all (unless you've got Macs on LocalTalk). We've got a Shiva FastPath
box to support our (aging) LocalTalk network, and, by extension,
printers that are only capable of LocalTalk connections. Any AppleTalk
printer with an Ethernet card is directly on our network. Macs "see"
those printers through the chooser. There's no spooling on the Client
Unix machines have many printers defined as being "remote printers",
and they submit their print jobs via the standard Unix print filters to
the Unix print server. The Unix print server runs CAP, receives those
print jobs, and sends them (via standard Unix mechanisms) to output
"filters" that are actually the CAP software. Those print jobs go out
on the Ethernet under AppleTalk-protocol. If someone on a Unix machine
was printing to a printer on LocalTalk, the FastPath box would see that
traffic on it's Ethernet interface, do the Ethernet=>LocalTalk
conversion, and send the AppleTalk protocol data to the printer.

                                     +---------------------+
      AppleTalk ethernet printer==1==| Ethernet hub/switch |
                                     | |
                mac on ethernet===2==| |
                                     | 5 |
                unix client=======3==| |
                                     | |
                unix print server=4==+---------------------+
                                                ||
                                                ||
                                      +-----------------------+
                                      | Ethernet to Localtalk |
                                      | conversion hardware |
                                      | (FastPath, GatorBox) |
                                      | |
                                      | 6 |
                                      +-----------------------+
                                              || ||
                                              || ||
                                              || ||
                                Mac on LocalTalk (7) ||
                                                          ||
                                                          ||
                                        Printer on LocalTalk (8)

LocalTalk Mac to LocalTalk printer
        Data goes from 7 ==> 8
                No protocol or media conversion

LocalTalk Mac to Ethernet AppleTalk printer
        Data goes 7 ==> 6 ==> 5 ==> 1
                6 does LocalTalk to Ethernet media conversion
                No protocol conversion

Ethernet Mac to Ethernet AppleTalk printer
        Data goes 2 ==> 5 ==> 1
                No protocol conversion, no media conversion

Ethernet Mac to LocalTalk printer
        Data goes 2 ==> 5 ==> 6 ==> 8
                6 does LocalTalk to Ethernet media conversion
                No protocol conversion

Unix client to Ethernet AppleTalk printer
        Data goes 3 ==> 5 ==> 4 ==> 5 ==> 1
                3 does text to PostScript conversion via printcap
                filtering, sends data to "remote printer" on server 4.

                4 does TCP/IP ==> LocalTalk protocol conversion

Unix client to LocalTalk AppleTalk printer
        Data goes 3 ==> 5 ==> 4 ==> 5 ==> 6 ==> 8
                3 does text to PostScript conversion via printcap
                filtering, sends data to "remote printer" on server 4.

                4 does TCP/IP ==> LocalTalk protocol conversion

                6 does LocalTalk to Ethernet media conversion

=> even if I get netatalk working? I was confused in the archives by this
=> issue. It seems some people were saying yes and that other said no, all you
=> need is netatalk. I realize of course that we could solve the problem on
=> the Mac side by buying the hardware bridges for each of the printers.

If the gatorbox does the Ethernet <==> LocalTalk conversion, it is a
hardware bridge. You might want to get individual print spoolers
(which are also hardware bridges) that only handle one device each.

=> Lastly, does anyone know if some of the bridges are smarter than others?
=> I.E. with a smart bridge wouldn't need netatalk on Unix.

I think you'd still need something in software (netatalk or cap or a
commercial solution) to do the conversion to the AppleTalk protocol
that the printer is listening for.

=>
=>
=> I tried to keep this short so I hope it doesn't sound too scrambled. I
=> believe those that will be able to help me are familiar enough with the
=> problem to have a pretty good idea of what I'm asking help with.
=>

My reply was kind of long, though short on specifics. I hope it
didn't confuse a confusing issue even more.

Really simple answer:

        If all your devices are on Ethernet, then you don't need the
        GatorBox at all. You will need to run CAP or netatalk on the
        Unix print server, however.

******************************************************************
Lisa Weihl, System Administrator Internet: lweihl@cs.bgsu.edu
Department of Computer Science Office: (419) 372-0116
Bowling Green State University Fax: (419) 372-8061
Bowling Green, Ohio 43403-0214



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