Abstract: A method for the clock recovery in transport in constant bit rate channels(CBR), especially suitable for implementation of the adaptation layer of the asynchronous transfer mode(AAL) which comprises: the use of means for temporarily storing data at receiving end; the use of a clock frequency, with which data are polled out from said storing means, and calculation of a series of time differences(Zk), characterized in that said difference series is sent to a control block where the instant value(Zk) of said differences is multiplied by the value of its own index(k); it is subsequently compared to the sum of the previous values(Zk) considered up to the moment(k−th value); and it is checked that the absolute value of the differences outcoming from said comparison is less of the error(err) multiplied by the index(k−1) of the previous value(Zk) and by the absolute sum value(sum). The invention refers also to an apparatus to carry out such a method.