Introducing BEA eLink TCP for IMS

BEA eLink products offer a set of communication gateways between BEA TUXEDO systems and other online transaction processing environments, including IBM's CICS and IMS. They allow applications to scale in size by providing interoperability between systems. The BEA eLink for Mainframe TCP for IMS (hereafter referenced as eLink TCP for IMS) product is a gateway connectivity feature that provides transparent communications between client and server transactions in an IMS system and a BEA TUXEDO domain, a CICS system, or another IMS system. (A BEA TUXEDO domain is a single computer [or network of computers] that shares a single BEA TUXEDO configuration.)

The following information introduces the eLink TCP for IMS product:

• Features/Benefits

• BEA eLink TCP for IMS Architecture

• BEA eLink TCP Functionality

• Required System Components

Features/Benefits

• Ensured online integration of business operations through transparent client/server communications among heterogeneous systems

• Truly open distributed applications

• High throughput through TCP/IP for online request/response messaging

• Ease of integration; modular architecture for flexible on-schedule migration

• High performance open solution

BEA eLink TCP for IMS Architecture

The eLink TCP for IMS product can execute as either a batch message processing (BMP) program that works in the IMS environment or as an open transaction manager access (OTMA) client running under OS/390. It uses the OS/390 TCP/IP Sockets API to communicate with a eLink TCP for TUXEDO gateway on a remote BEA TUXEDO system, and the IMS message queue (directly or indirectly through OTMA) to communicate with IMS transactions. This product supports connectivity with remote eLink TCP for TUXEDO gateways, eLink TCP for CICS gateways, or other eLink TCP for IMS gateways. Figure 1-1 illustrates connection with a remote eLink TCP for TUXEDO gateway.

Figure 1-1 The BEA eLink TCP for IMS Interoperability Solution

The configuration definition of the eLink TCP for TUXEDO gateway in the remote BEA TUXEDO system maps BEA TUXEDO local services to remote services provided by the IMS gateway. Each remote service corresponds to an IMS server transaction. Service requests issued by clients in the BEA TUXEDO system are routed through the eLink TCP for TUXEDO gateway to the eLink TCP for IMS gateway for processing by the appropriate IMS server transaction.

Similarly, the configuration definition in the eLink TCP for IMS gateway maps local service names to remote services provided by the BEA TUXEDO system. Service requests issued by IMS client transactions are routed to the eLink TCP for TUXEDO gateway for processing by the appropriate BEA TUXEDO service.

In both cases, access to a remote service is transparent to the client requesting the service.

BEA eLink TCP Functionality

The following functionality is available in the eLink TCP product.

Domains-based Gateway Connectivity

The eLink TCP product has a domains-based architecture supporting bidirectional communications, request/response support, and concurrent support for IMS BMP and OTMA interfaces.

Security

The eLink TCP product grants access to TUXEDO services based on a user name that the remote gateway supplies.

The eLink TCP for IMS product has an OTMA interface that supports enhanced security. This interface allows a requester from TUXEDO to pass a USERID through the OTMA server interface for authorization through the third party security package.

For more information about configuring security, refer to "Monitoring BEA eLink TCP for IMS."

Domain Name Server Support

The eLink TCP product supports domain name server (DNS) resolution of IP addresses. This support allows you to change the IP address at the domain name server to implement address changes without reconfiguring the eLink TCP gateway.

Dynamic Configuration

The eLink TCP product supports dynamic configuration updates of the eLink TCP configuration parameters. You can modify the configuration without shutting down and restarting the eLink TCP product.

Required System Components

The eLink TCP for IMS product requires the following components for transaction processing.

BEA eLink Gateway Program

The eLink TCP for IMS product can execute as a standard, transaction-oriented batch message processing (BMP) program that works in the IMS environment or as an OTMA client running under OS/390. It uses the OS/390 TCP/IP sockets API to communicate with remote BEA eLink gateways and the IMS message queue (directly or indirectly through OTMA in the case of the OTMA client) to communicate with IMS application transactions.

IBM LE/370

IBM LE/370 provides a common runtime environment for a number of IBM high-level languages, including C/C++. The eLink TCP for IMS gateway is written in the C programming language and requires the LE/370 runtime environment.

IBM TCP/IP for OS/390

IBM TCP/IP for OS/390 provides TCP/IP communications support for programs executing in an OS/390 environment by means of a standard, UNIX-style socket API. The eLink TCP for IMS product uses TCP/IP to communicate with remote BEA eLink gateways.

Note: This guide assumes you are using the IBM TCP/IP for OS/390 product. If you are using another supported TCP/IP product, such as Interlink TCPaccess, consult the product documentation for equivalent components.

IMS Server Transactions

IMS server transactions are user-written programs that process service requests issued by a remote system. Server transactions are ordinary IMS transactions and can be written in any language supported by IMS. For supported languages, refer to the IBM IMS manuals.

IMS Client Transactions

IMS client transactions are user-written programs that issue requests for services offered by a remote system. Client transactions are ordinary IMS message processing program (MPP) transactions and can be written in any language supported by IMS.