OSI/MHS Orientation Guide

Building Your Message Handling System
OSI/MHS Orientation Guide—424829-001
1-23
Integrating Your Own Messaging System With
Compaq OSI/MHS
Integrating Your Own Messaging System With
Compaq OSI/MHS
One of the most common uses of X.400 message handling systems is to integrate
existing messaging systems—for instance, proprietary electronic-mail systems, public
telex systems, and even physical delivery systems—over a standard network. To
communicate across an X.400 network, an existing messaging system needs a gateway.
What You Need to Do
To integrate an existing messaging system with OSI/MHS, you develop a gateway to
translate messages between X.400 and the other format, and to move messages from one
environment to the other. For this purpose, you can use a Compaq product called the
Gateway Programmatic Interface (GPI). An application that uses the GPI is called a
GPI client.
The GPI has two parts, as illustrated in Figure 1-7:
•
A procedural interface callable from applications written in C or TAL (the Compaq
proprietary programming language). This interface is based on specifications
defined by the X.400 Application Program Interface Association (XAPIA).
•
A process called the Gateway Interface Process (GIP), which supports the
procedural interface by receiving requests and moving messages between your
application and the MTA within OSI/MHS.
A gateway developed with the GPI emulates some functions of a 1984 or 1988 MTA. A
specialized type of gateway called a P1 user exit gateway lets your application intercept
messages as they arrive in the system, and then optionally submit them to OSI/MHS for
processing.
After you develop your gateway, you can define your OSI/MHS configuration to include
it as a GATEWAY object.