The invention relates to producing data traffic where the time intervals between successive data frames follow a predetermined probability distribution. In the present invention, it is surprisingly discovered that a time interval of a desired length between successive data frames can be produced by setting a certain bit quantity of digital stuffing data, defined on the basis of the target length of the time interval target, in a buffer memory (101), where successive data frames are waiting to be transmitted. The digital stuffing data is set in the buffer memory (101), so that the stuffing data is, in the read-out order, located between successive data frames.