barry@adelie.UUCP (04/02/87)
(I apologize for the length and wide cross posting, but I figure that this
article may be of various interest to different parties, as well as wanting as
big an audience as possible...)
My company selss a distributed application which manages a distributed,
hierarchical database in a non-homgeneous environment of IBM MVS Mianframes
(CICS or IMS), DEC Vax (Ultrix) or AT&T 3Bx (System V) minicomputers, and IBM
PC's (now that's a mouthful!). [Before you call- we sell the Application, not
the distributed database- they're Very Closely Integrated, by design]
Lacking readily available LU6.2 three years ago when we began the PC component
of the distributed database, we `standardized' on implementing our
PC->Mainframe link by developing a proprietary database synchronization
protocol based upon an interactive communications session between the two
systems. The initial transport vehicle was based upon DCA IRMA cards (ie. 3278
emulation), carrying on a PC-initiated "database synchronization" conversation
directly with an On-line CICS/IMS transaction through normal 3278 screen
read/writes:
("Hello- I'm PC:xyz<enter>. Do you have any database changes I should know
about?<enter> No, I don't have those yet<enter>. Please send that Now<enter,
etc.>. OK Thanks- here is some stuff I'm sure you'll be interested in:...Got
that? OK, is there anything in what I just sent you that's unacceptable? OK,
let me fix that. Anything else? Ok, bye!")
This is all fine and good and working quite well. Our next product implemented
the same protocol between a 3B2/400 and the mainframe through AT&T's ISC card
and the SNA/Emulator+ and API software (a nightmare in itself). Also not too
bad (except that now that it's done, AT&T announces LU6.2 support...Just In
Time!).
Now I need a transport vehicle for MicroVAXen, Unibus VAXen, and BI-Bus VAXen,
all running Ultrix (or BSD4.2/4.3), and I'm looking around for alternatives.
Not surprisingly, there aren't many end-user products out there yet for Unix
that will plug-in readily to an existing IBM DP-shop environment (TCP/IP, etc.
for the Mainframe isn't an option in most MIS environments). Several companies
will license software ports, but these are generally priced and packaged for
Manufacturers/OEM's, something we are not yet ready to become (commit to sell
How Much in the next 3 months?- Bah!).
So....
I would appreciate any/all information about and/or experience with SNA
interfaces for VAX UNIX. External 3278 terminal emulators are of little use,
since it's my Application that needs to do the talking, hence API(3278) and
APPC(LU6.2) in the Keywords, above. I would prefer a family of cards
(Unibus/Q-Bus/BI-Bus) for the VAXen, along with 3278 terminal emulator
software AND an API (applications program interface) through which my
applciation can read/write screens. LU6.2 APPC would be even nicer, but not
my first requirement.
One option I know of is the Mitek Network Servers, which one can access via an
API over TCP/IP Ethernet. Neat, non-vendor specific solution (so long as
TCP/IP is available), but somewhat expensive for the low-end MicroVAX
configurations.
Please MAIL me any information on vendors and experiences- I will summarize fo
the net in "comp.misc", lacking a specific "comp.dcom.SNA" group (one day
we'll have one of those, too. I'm sure).
Thanks!
--
LIVE: Barry A. Burke, (617) 499-6370
USPS: Adelie Corporation, 125 CambridgePark Drive Cambridge, MA 02140
UUCP: barry@adelie.Adelie.COM / ..!{harvard,ll-xn,necntc,mirror}!adelie!barry
ARPA: barry@adelie.Adelie.COM (via MX) / barry%adelie@harvard.Harvard.EDU