Linux SNA server question

[Jonathan Claxton]

On Tue, 4 Mar 2003, christian ruckdaschel wrote:

> Does anyone have any experience with 3270 emulators or SNA servers?
> My question is this:
> My company is looking to replace a bunch of old 3270 terminals with pc's
> (the monitors are failing on the terminals).  What I want to do is use a
> single Linux box with a single 3270 pci card interfaced with OS/390 and
> network (ethernet) that box with several others running 3270 emulation and
> have multiple consoles.  Is this possible?  Have I confused anyone?
> Any help would be greatly appreciated.
>

First of all.... let's seperate the two kinds of 3270... SNA and
NON-SNA(BiSync).

NON-SNA.
This is the kind where each terminal has it's own DEVICE ADDRESS. This has
to be handled by a controller unfortually(sp). Now.. there is a controller
called 2704 that will let users with a TN3270E emulator to telnet into
this box and become a Operator Console. This box runs OS/2 with channel
interface cards that costs like $12,000 apiece!!!

SNA.
As for the SNA. Yes, you can setup Linux boxes that people can run the
TN3270E emulator and use that to telnet into the OS/390 system and it will
mostly work just like a real 3270.  The connection from the Linux box to
the OS/390-z/OS basically has to be on ethernet. The latest z800 or z900
boxes can be equipped with ethernet connections either at 100megabit/sec
or 1gigabit/sec. Also, the 3270 emulator is open source program found on
RH and other distributions.  If it not on the dist that you chosen to use,
one can download it and compile it. Also, this program comes in a
cheracter or graphical mode programs.

Also, the OS/390-z/OS system has to have the TCP/IP stack setup for
TN3270. At work, we use this on production systems and all together, more
than 6,000 users are using TN3270 across 6 z900 partitions(systems) and it
hardly uses much CPU cycles.

Now... as for a SNA Controller-type software running under Linux....
well....  there is someone writing a SNA stack that will run a SNA
connection to a OS/390 or to a Front-End processor. But I would not use
this since IBM has basically said, "Go TCP/IP and DROP SNA" for terminal
use. SNA is still used to internet-connection OS/390-z/OS systems so that
users on one system can access applications on another system.


Now.. after all this, glad you have someone that knows about all this and
definally not confused?
:)