Abstract: A gateway and method for distinguishing between different types of messages without requiring the gateway to be fully aware of the communication protocol. The gateway passes through messages from application entities to network elements and vice versa. The gateway determines a transaction identifier or sequence step information, and compares the transaction identifier or sequence step information with ones previously stored. The comparison result is used to determine whether a message is an initial message or a response message to the initial message, and whether the message is a first or subsequent message, respectively.

Abstract: A simple gateway and an improved controlling method for controlling said gateway are provided to distinguish between different kinds of messages without requiring the gateway to be fully aware of the protocol. The gateway (200c) passes through messages from application entities (310, 320) to network elements (100) or vice versa. The gateway (200c) comprises a transaction identifier determinator (220) to determine a transaction identifier and/or sequence step information determinator (260) to determine sequence step information and a control logic (280) that compares the transaction identifier and/or sequence step information with previously stored ones. From this comparison, it can be determined, whether a message is an initial message or a response message to the initial message and whether the message is a first or a further message, respectively.