DYNAMIC MESSAGE INTERFACE

In a telephone exchange the functional units of call control communicate by way of a common message bus. If a unit wants to know only one thing from the data of a message, then due to the fixed structure of the message all other data contained in the message must also be received. Unnecessary data is thus transmitted in the message bus. The procedure according to the invention is such that the service requester states in the request message exactly what it wants to know. Since the data structure of the service provider, that is, the position of each individual data and the length of the data field, is known to the service requester, only those entries of the data structure are stated in the request message where the requested data is located. The service provider fetches only this data from its data structure and sends it in the reply message to the message bus. Thus, both the request message and the reply message form a dynamic message pair.