| |
APTNet: An Innovative SNA/Internetwork Solution
By Anura Guruge
Special to LAN Times
APTNet from Automated Programming Technologies Inc.
(APT) is an innovative solution for LAN/WAN internetworking across existing low-speed
Systems Network Architecture/Synchronous Data-Link Control (SNA/SDLC) links.
APTNet lets LAN users perform a wide range of LAN-to-LAN operations
across an SNA WAN backbone. These operations include remote file-server access, remote
printing, file-transfer management, automated software distribution, remote end-user
support (via remote-workstation "mirroring" or takeover), real-time interuser
electronic messag-ing, and networkwide message broadcasts.
APTNet supports data-transfer and remote print-ing functions between
LANs and IBM hosts. Hosts are treated as virtual LANs, and little distinction is made
between LAN-to-LAN and LAN-to-host.
APTNet's support of non-SNA connections lets notebook-computer and
home-PC users dial in to APTNet and function as if they were on a LAN-attached PC.
The APT solution is fundamentally different from other, relatively
well-known solutions for SNA based LAN-to-LAN interconnnection, such as Novell's INc.'s
SNA Links and IBM Corp.'s LAN-to-LAN WAN Program.
These solutions provide function- and application- independent
generalized LAN inter-connection,albeit for a limited set of LAN protocols (typically
Novell Inc.'s IPX/SPX, TCP/IP, and NetBIOS).
Such solutions are functionally equivalent to conventional
bridge/routers from such vendors as Cisco Systems Inc. and Wellfleet Communications Inc.
They differ only in using SNA as their router-to-router protocol.
In contrast, APTNet does not provide generalized LAN interconnection.
Instead, it supports the most heavily used (and rele-vant) inter-LAN operations in a way
that maximizes typical 9,600bps links, 19.2Kbps links, or-in some cases-the even slower
SNA/SDLC WAN links.
Consequently, APTNet may not support some inter-LAN database-management
applications. (APT offers an application programming interface, or API, and customized
development projects to deal with these applications.)
FEATURES
APTNet is based on a client/server architecture and consists of the
following three software components:
 | Software that runs on the client PCs;
|
| Software that runs on nondedicated, "communications-server"
PCs, which are the interface between individual LANs and the SNA network; and
|
| IBM host software, which is in the form of a standard Advanced
Communications Function/Virtual Tele-communications Access Method (ACF/VTAM) application.
|
The host software provides LAN-to-LAN and LAN-to-host
routing functions. SNA LU-LU Type 2 sessions are used between this software and the
communica-tions servers.
Instead of the conventional 3270 protocol, an APTNet-specific protocol
that encapsulates LAN-to-LAN traffic is used across the SNA sessions.
These sessions are established using external and, most likely,
already-in-place SNA LAN gateways. An APTNet SNA LU 6.2-based version that does not
require host software (unless you need LAN-to-host functions) is scheduled for release
this year.
Once APTNet is installed and con-figured, users can perform inter-LAN
and LAN-to-host operations just by using remote-node (LAN) names, remote-drive letters,
and remote-printer names. You can even configure a network so users are unaware of
APTNet's presence or that some LAN-to-LAN functions are being conducted across an SNA
network.
In this respect, APTNet is well-suited for branch-office integration,
where user-friendly, low-cost networking is required. APTNet is even more compelling to
those companies with an SNA backbone that reaches out to all their branch offices.
APTNet is also useful in implementing help desks for LAN/WAN
in-ternetworks. Its workstation "mirroring" and takeover facilities let
central-site operators look over the shoulders of remote users experiencing problems.
NETWORK AWARENESS
Because APTNet is a self-contained "virtual network" with only a
few dependencies on external ser-vices, it works independent of network operating systems
(NOSes), LAN protocols (such as Novell IPX/SPX and Net-BIOS), and SNA LAN gateways. You
can use APTNet for LAN-to-LAN interconnection in NetWare, OS/2, LAN Server, or VINES
environments. It can also be used in native DOS or Windows mode for inter-LAN file access
or remote printing. With APTNet, every client PC must run APTNet-specific software.
Conse-quently, APTNet supports clients that run only DOS or Windows. This is different
from other LAN-interconnection techniques, which require each client PC to run an
appropriate NOS. (Support for other clients, such as OS/2 and Windows/NT, is planned in a
future release.)
But to handle its compacted protocols, APTNet must be able to intercept
requests for inter-LAN services at the client PC. These protocols let APTNet consistently
deliver acceptable inter-LAN performance even when using low-speed SNA/SDLC links without
adversely affecting the performance of the host-to-PC 3270 sessions that also use these
links.
NETWORK MANAGEMENT
APTNet provides numerous, customizable network-management and
security features, as well as activity-logging and file-transfer-audit-ing features.
Because APTNet's inter-LAN and LAN-to-host connections are realized using standard SNA
sessions, you can manage and monitor the overall APT-Net topology using IBM's NetView/390
resident software on an IBM host.
INSTALLATION AND USE
You must separately install each APTNet component. The installation
process, including that for the host software, is straightforward and rigorously
documented. A remote installation process simplifies the installation of client-PC
software. You can easily configure, operate, and man-age the network by using a series of
self-explanatory, APTNet specific windows.
DOCUMENTATION
The tutorial-like documentation consists of a succinct-though
informative Getting Started guide and a 300-page User's Reference Manual Both documents
provide tips and shortcuts annotated using a series of icons. The Getting Started guide
begins with a six-page, incisive introduction to contemporary LAN/WAN internetworking that
will be of great value to novice users.
APTNet
5 Nodes
| Criterion |
Weighting |
Score |
| Features |
250 |
4 |
| Network Awareness |
250 |
4 |
| Network Management |
200 |
5 |
| Installation/Use |
200 |
5 |
| Documentation |
100 |
5 |
How we score: Products are rated on a scale from
Unacceptable to Excellent, based on the following criteria:
Excellent: 5 nodes-Stellar, top-of-the-line product.
Good: 4 nodes-Meets all standard criteria and includes some special
features.
Satisfactory: 3 nodes-Meets essential criteria and does everything
it's expected to do.
Poor: 2 nodes-Falls short in essential areas. 2 nodes-Falls short in essential areas.
Unacceptable: 1 node-May have some working features, but is seriously
flawed.
We multiply the weighting, or importance, assigned to each category by the
product's scores in each category, sum the results, and divide by 1,000 to come up with a
final score between 1 and 5. Products' final scores are assigned a certain number of nodes
to reflect their final ratings. For example, a product with a final score of 4 would
receive 4 nodes. (To personalize this chart, use your own weighting and follow this
formula.) |
Company:
Automated Programming Technologies Inc. 30100 Telegraph Road Suite 402
Bingham Farms, Ml 48025
Sales: (800) 877-8765
Fax: (810) 540-0403
Pricing: $5,000 for the host
(MVS, VM, DOS/VSE)
software; $400 per host
connection; $300 for the
client software
Summary: APTNet is a highly optimized, low-cost, high-performance solution for LAN/WAN
internetworking across existing, low-speed SNA/SDLC links. APTNet does not provide
generalized,LAN-to-LAN interconnection. Instead, it supportsthe most heavily used
inter-LAN operations. |
Reprinted with permission from LAN TIMES, September 20, 1993.
Copyright 1993 by McGraw-Hill, Inc.
All Rights Reserved. For reorders --- call 612-633-0578.
|
