Off Board Server

Scenario:
You need to connect to a legacy mainframe system. The source code is not available, the database cannot be accessed directly.

Possible architecture:
A Java Socket server is produced to enable secure remote access to the mainframe by forwarding SSL requests sent on sockets to serial connections on the mainframe. Responses are transmitted back to the client via SSL.

Pros:

• Enables secure remote access to mainframes, typically done by forwarding SSL requests to the mainframes via serial connections.

Cons:

• They are not application servers, meaning that they cannot take on complex business logic

Alternatives:
A screen scraper can also be appropriate for this scenario.

Off Board server
An off-board server is a server that serves as a proxy for a legacy system.
It communicates with the legacy system using the custom protocols supported by the legacy system. It communicates with external applications using industry-standard protocols.