Applications participating in an OLTP environment use standard buffers for sending OLTP messages and receiving OLTP responses. If your application has been defined as an OLTP Server, it can use the same mechanism to communicate with an external OLTP client. Your application can receive OLTP requests from the OLTP client, and respond to them without being aware that the client is an external application.

However, in order to communicate in a similar manner with external OLTP Servers, you must define a special interface in your application. A data format, held in a file called an OLTP Buffer description, is stored in a class called an OLTP View class. This format is then used by your application to correctly structure the OLTP requests it sends to an external OLTP Server, and to interpret the OLTP responses it receives from such a server.