To provide CTI services or features via a communication channel having a plurality of communication connections, after communication of a request for a CTI service or feature for a selected communication connection, an assignment between a device ID, a connection ID and the requested CTI service or feature is established. A control sequence for setting the requested CTI service or feature is invoked, specifying an assignment identifier designating the assignment between the device ID, the connection ID and the requested CTI service or feature as the transferred parameter. The control sequence invoked is processed with evaluation of the assignment identifier to provide the requested CTI service or feature.