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PAGE O2

puter hardware,
software, data-
ments and, com:
municattons eh-
Corporations <
are moving rap-
idly toward im-

UAMES
MARTIN | plementing large-
scale strategic

systems that integrate all components of
an enterprise. These complex systems
will be based on the installation of net-
works capable of supporting large num-
bers of PCs, file servers and links to
mainframe systems. Both data and pro-
cessing modules will be distributed |
throughout the network in cooperative-
processing and client/server appli-
cations.
| Large corporate networks of comput:
ers are being implemented both to com-
puterize entire organizations and to es-
tablish intercorporate links with suppli-
ers, retailers, customers, dealers,
distributors and financial organizations.

Among the communications mecha-
nisms used are E-mail for person-to-per-
son interfaces; electronic data access for
person-to-application interfaces; and
electronic data interchange for applica-
tion-to-application interfaces.

Many corporations have greatly in-
creased the strategic value of their com-
puter systems through intercorporate
networks used for electronic data inter-
change. These networks have enabled
them to reduce trading delays, provide
better customer service, increase their
competitiveness in the market; and re-
duce costs. In addition, these networks
can reduce transportation expenses, im-
prove production scheduling and de-
crease waste.

In addition to building networks of
PCs and mainframes, organizations will
link other communications functions

and make them accessible through the
PC. Voice mail, E-mail and fax will all
be access] ble through the individual's
PC. Gateways to outside networks will
be used to tie into real-time news wires,
To build these complex networks,

zapove te OE lene to
, processing power of local PCs must —2.

the process'

technigue to imple-

orks. LANs will utilize

PCOs at the rate of 100M bps.
»grated bervices Digital

spread use of ISDN will facilitate
vide simpler access to highspeed.
switched digital circuitg.

To implement corporatewide commu-
nications networks, the current incom-
patibilities between hardware and soft.
ware systems must be resolved. Despite
major commitments to international

communications protocols, problems still
exist in linking hardware ie software
systems f different: vendors.
k obesim ustrates the type of inter"
connections that are available to link
both IBM and non-IBM systems. The ex:
araple shows communications interfaces
between SAA applications, applications
running under AIX (IBMs version of
Unix) and other systems (such as Sun
workstations under Sun OS, Unix
workstations under Unix System V or
DEC VAX computers under VMS).

To communicate effectively among
these diverse systems, it's necessary to
specify multivendor architectures that

define a standard set, of networking ser-

NPPLJED INTELLIGENCE
[Integrated Multivendor Solutions Are Crucial to Networking

Standard Networking Services Reguired

CPE IEEKNAPPLIGATION DEVELOPMENT H

ments, together with OSI international

protocols, implement the SAA cormmuni-

As discussed in a previous article,
SAA provides a comprehensive set of
facilities to distribute both process and
data across IBM PS/2, AS/400 and Sys-
tem/370 computers. Interprocess com:
munications between IBM machines 15
supported by SNA conventions, includ-
ing Synchronous Data Link Control |
(SDLC), LU 6.2 peer-to-peer communica:
tions protocols and Token-Ring LAN
protocols. Access of data located on re-
mote, non-IBM computers is supported

within SAA through the use of standard

OSI protocols including X.25 packet

For Enterprisewide Interconnectiohs

The Standard Data-Tranisfei' Protocol Is Based oi SGL;
Standard Communications Protocols

dl pa a a a Sao

SAA NU
application

H
j

ZNE NA Ek
7 A ŽA, repiip, osi

V.

Itielude SNA, TCP/IP atid OSI

| SNA, TCP/IP, OSI >

o

Othet
applications

John Avakian

Many corporations have greatly increased the strategic
value of their computer systems through intercorporate

— Vices, data-transfer protocols an a-
transfer media. The figure selena
representative multivendor architecture
based on SOL-compatible data-access

- standards and communications proto-
poki supported by IBM's SNA, TGP/IP

po Open Syplema juter Interconnect (OSI) in.

nm tions protocols.
se Systems Network Arohitecture
Systema Application Architecture (SAA)
and is used to support, communications:

JC m a distributed | | OTV

The SNA not rorking area done

pgen used by IBM for years to intercon.
dissimilar systems. These SNA ele-

networks used for electronic data interchange.

switching, X.400 electronic mail and
TEEE 802 Token-Ring.

TCP/IP is widely used to support, net:-
works for military applications, univer-
sities, research laboratories and manu-
facturing applications. Implementations
of TCP/IP include the Ethernet LAN
based on the Berkeley variant, of Unix,
as well as wide area networks using
X.25 packet-switched networks for a
wide variety of popular computers.
The OSI communications model is
based on standards defined by the Inter-
national Standards Organization. The or-
ganization has defined a seven-layer OSI
model that forms the basis for a net:

Standard protocols defined using the

JUHE 11, 1990

working architecture. Fach layer has a

OSI model include X.25 packet switch-
ing, X.400 E-mail, IEEE 802 Token-Ring
and Connectionless Network Protocol
used in factory-floor manufacturing op-
erationS.

TCP/IP is widely used to support
Ethernet, LANSs; the OSI model is fre-
guently used for X.29 packet-switched
networks.

It's likely that the OSI model will
grow in importance relative to TCP/IP.

Supporting Communications

The three applications environments

shown in the figure—SAA, AIX and non:
IBM applications—generally support one
or more of the communications environ-
ments shown in the figure—SNA, TCP/IP
and OSI The communications-support ca-
pabilities of the three applications envi-
ronments are summarized below.

SAA applications utilize the SNA net:
working architecture to provide connec-
tivity between PS/2, AS/400 and Sys-
tem/370 computers. TCP/IP and OSI
protocols are used to support communi-
cations with non-IBM machines.

IBM's ALX is a variant of Unix that <
supports a basic multiuser, multitasking
environment. In addition, it provides
support for virtual memory, enhanced
file management, dynamic configuration,
support in the DOS environment for
multiple users, multiple interactive ses-
sion management and National Lan-
guage Support.

Communications support for AIX in-
cludes TCP/IP, X.25 packet, switching,
Sun Network File System (NFS),
Ethernet, and Token-Ring LANS, and
electronic-mail protocols. These commu-
nications facilities enable AIX applica-
tions under Unix to integrate well with
SAA applications under OS/2.

Broader integration between IBM and
non-IBM machines may be obtained
through support of TCP/IP and OSI net-
work architectures. Many computers,
such as engineering workstations and
Digital VAX systems, provide support
for TCP/IP and OSI protocols. The use of .
standard communications protocols and
standard data-access conventions should
be strongly encouraged to provide
interoperability between widely diverse
computer environments.

Next, week, Ill discuss how these ma-
jor trends in computer hardware, soft-
ware, database and communications en-
vironments are affecting the evolution
of computer drchitectures. H

The concepts embodied in this article
are described in the High-Productivity
Technology volume in The James Mar-
tin Report Series. For more informa-
tion on this volume, call (617) 639-
1958. For information on seminars,
contact (in the United. States and Can-
ada) Technology Transfer Institute,
741 10th St., Santa Monica, Calif.
90402 (213) 394-8305. In Europe, con-
tact Savant, 2 New St., Carnforth,
Lancs., LA5 9BX United Kingdom
(0524) 734 505.

specific set, of respo nsibilities within the či,