White
Paper - Alliance Series TCP/IP
Overview
Alliance
Series TCP/IP is designed to assist the AS/400
customer with connecting PCs, Internet applications,
workstations, and other hosts to the AS/400 using
standard TCP/IP communications. Customers can deploy
Visual Basic, Access, Internet Web CGI or ISAPI, C/C++
and other types of client/server applications that
connect to the AS/400 without special communications
programming on the AS/400. Client applications send
data to the AS/400 via a TCP/IP Sockets connection and
receive data back from user-written RPG or Cobol
applications. The client application programmer uses
standard TCP/IP sockets functions to connect to the
AS/400. Alliance provides the AS/400 TCP/IP server
interface and talks to AS/400 applications via data
queues. The AS/400 RPG or Cobol programmer reads the
client request from a data queue, performs application
processing, and returns data to the client via a
response data queue. Alliance performs all of the
communications, data translation, and management
functions. With Alliance, no communications expertise
or ILE C/400 programming is required on the AS/400.
Client/server applications can be deployed quickly
that take advantage of intranet and Internet networks.
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The
Internet provides a way for your employees, business
partners, and customers to communicate with you from
anywhere in the world. Many types of Internet
applications are available to help you do this. These
include the World Wide Web (Web), FTP, SMTP Mail, and
others. You can also create your own applications that
communicate over the Internet. These applications can
be created with Microsoft Visual Basic, Access, C/C++,
Delphi, and other tools to provide a customized
interface to your host systems.
Alliance
TCP/IP can help you integrate the AS/400 with your
Internet applications by providing server functions on
the AS/400. You do not need to implement a Web server
on the AS/400 or open your AS/400 to Internet access.
If you are deploying Web applications on a UNIX or
Windows NT server you can write CGI (Common Gateway
Interface) or ISAPI (Internet Server Application
Program Interface) programs that communicate with
Alliance TCP/IP on the AS/400. The Web application can
send a request to the Alliance and a response will be
returned from your business application. Your AS/400
business application can update or retrieve
information in a local database, or can initiate
communications with other systems to provide a
response.
If
you are deploying custom applications that communicate
over the Internet, Alliance TCP/IP can be your
application server. Alliance can handle multiple
simultaneous requests and provide rapid response to
your remote applications. Using Alliance you can
implement additional security checks for data access
or update. [top]
If
you have a requirement for networked applications
inside your company or on a private connection to a
business partner, Alliance can assist you with this
connection, too. The communications interface for
private internets or intranets is the same as for the
Internet. All of the functions described in the
section above on the Internet are available for local
intranet or private internet applications. [top]
On
the AS/400 Alliance TCP/IP provides all of the TCP/IP
communications interfaces to the TCP/IP network.
Alliance configures the IP addresses and ports
required by the network for the connection and
provides automated management functions to start and
stop communications support. Full communications trace
and application logging functions are integrated with
Alliance for ease of use and rapid development.
Alliance provides all of the network interface
functions, data translation, and application
interfaces. AS/400 developers can focus on the job of
providing access to AS/400 data and application
functions. [top]
Alliance
TCP/IP also provides client services for AS/400
programs. If your AS/400 application needs to initiate
a connection with another system you can use the
Universal Client application shipped with Alliance or
create your own client applications and register them
with Alliance. The Universal Client receives address
information and data, connects to the remote system,
sends the data, receives a response, and returns the
response to the AS/400 application that made the
request. You can implement complex AS/400
client/server applications with no communications
programming.
You
can also create your own TCP/IP sockets applications
and register them with Alliance. Alliance will then
start and manage your application and provide optimum
performance. If you do not have in-house
communications support, Townsend can provide custom
programming services to help you meet your
communications needs. [top]
Alliance
is easy for an AS/400 programmer to use. When
transactions are received from the client Alliance
translates the data to EBCDIC and writes it to a data
queue. The AS/400 programmer simply reads the
transactions from the queue, performs application
processing and database functions, and returns a
response to a data queue. Alliance takes care of
converting the data to ASCII, sending the data back to
the client, and managing the communications session.
Alliance
performs all AS/400 communications configuration
functions for the server application. The AS/400
programmer does not need to configure line
descriptions, controllers, or devices. In addition,
Alliance performs all communications error detection
and recovery functions.
In
order to support problem determination, Alliance
provides the option of detailed session logging. When
logging is active all data and communications activity
is written to a file. Individual sessions can be
logged and there is a built-in communications trace
facility. These functions can assist a programmer
during the development phase. [top]
A
PC programmer can use Visual Basic, Access, C/C++,
PowerBuilder, Delphi, and other products to develop
applications. Any PC development product can be used
that provides access to the Windows built-in WinSock
communications APIs or for which there are third party
tools to perform standard TCP/IP communications. In
the Visual Basic environment, the programmer can use
communications OCX controls or the Windows Sockets
APIs. The programmer uses these PC communications
functions to connect to the TCP/IP network, send and
receive data, and disconnect from the network.
Microsoft and others provide sample applications and
source code to assist in developing applications.
Other
PC platforms, such as OS/2 and Macintosh, can also
access the TCP/IP network via communications functions
and third party products available on those platforms.
No special communications protocols are required, and
any standard Sockets interface can be used. [top]
A
Web developer can use CGI or ISAPI programs to
communicate with Alliance on the AS/400. If the Web is
implemented on a UNIX server the programmer can use
CGI applications and the BSD Sockets interface to
communicate. If the Web is implemented on a Microsoft
Internet Information Server the developer can use
either CGI or ISAPI to communicate with Alliance. In
either case the programmer is using standard tools for
communications on their respective platforms. [top]
A
UNIX programmer can use standard BSD Sockets to
communicate with Alliance on the AS/400. This
interface is included in all versions of UNIX and
supported by all UNIX compilers. BSD Sockets is the
standard for interplatform communications in a UNIX
environment. [top]
The
Alliance communications modules are designed to have
minimal impact on AS/400 performance. The
communications tasks do not consume CPU or disk
resources while waiting for connections. All Alliance
applications are written in the ILE C/400, and CL
languages, and are optimized for AS/400 performance.
Call
set up times on TCP/IP connections are extremely fast
and normally take a few milliseconds. Alliance loads
the communications modules and makes them available
while waiting for a connection. It is common for a
complete transaction to take less than a second on the
AS/400, depending on the speed and activities of the
user application. A transaction includes the
acceptance of an incoming connection, receiving data,
processing by the AS/400 application, returning a
response to the client, and closing the connection.
Connection set up times are much faster than SNA/APPC
connections and provide optimal response to remote
applications.
On
the AS/400 Alliance runs in its own subsystem and with
its own execution class. AS/400 customers can tailor
the operating environment without impacting other
application systems. Since most transactions processed
by Alliance will be interactive in nature, the
execution priority on the Alliance jobs can be set
safely at interactive priority. However, Alliance
users can configure the execution priority of any job
in the Alliance system. [top]
Alliance
is designed to run as an unattended application on the
AS/400. The application runs in its own subsystem and
can be started automatically during IPL by starting
the subsystem. An auto-start job will initiate the
communications jobs. The Alliance menu provides
several options for viewing the status of
communications jobs. A single interface allows for
viewing the configuration status, job status, job log,
and application log for any process in the system.
During normal operation Alliance will not require
operator intervention. [top]
The
AS/400 connects to the TCP/IP network with one or more
LAN adapters or network interfaces. No other hardware
is required for the AS/400. [top]
The
client system needs a standard LAN adapter (Ethernet
or Token Ring) or dial TCP/IP interface in order to
make a connection to the TCP/IP network. No other
hardware is required at the PC to make the connection.
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Alliance
runs on OS/400 V5R1 or later. The TCP/IP
communications support required for Alliance is
included in the base OS/400 operating system. No
additional AS/400 software features are required to
use Alliance. [top]
The
client system must have TCP/IP protocol support
available for a connection. This support is included
in the Windows For Workgroups, Windows95, Windows NT,
OS/2 and Macintosh operating systems, and via third
party products for Windows 3.1. No additional software
is required to communicate with Alliance on the
AS/400. The customer may purchase third party
communications products (VBX controls, OCX controls,
function libraries, etc.) to support application
development if desired, but these are not required. [top]
Initial
support is free of charge for 90 days. An annual
support agreement is available which includes new
releases and program fixes. Support is provided during
normal business hours. Extended hourly support is
available under separate agreement. A source code
license is available, as well as a third party source
code archive option. [top]
Patrick
Townsend & Associates, Inc. provides consulting
services to assist customers in deploying Alliance FTP
Security. These services are provided under a standard
consulting agreement and are arranged as needed. [top]
Patrick
Townsend & Associates, Inc. is a Washington state
corporation. The company specializes in communications
products and communications consulting services for
the Windows NT Server, IBM AS/400, and IBM mainframe
environments. Business partner companies include IBM,
Novell, Microsoft, Lotus, Infinite Technologies, and
others. Founded in 1984 the company has provided
services for Bank of America, Visa International,
Viking Freight, Roadway Regional Group, IBM
Corporation, Novell, Safeway, PMI Mortgage Insurance,
and many others. For more information and product
pricing, contact: Patrick Townsend & Associates,
Inc., 406 Legion Way SE, Suite 300, Olympia, WA 98501.
Voice: (360) 357-8971. FAX: (360) 357-9047.
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