Patent ID: 6901054

Claim:
A method for checking the transfer of data cells in an asynchronous switching arrangement ( 1 ), said method comprising the steps of: marking and counting cells received; and counting the cells, after switching when outputted from a switching structure ( 2 ) of the arrangement, in order to verify that the counts correspond and to find transfer errors of data cells due to unacceptable delays, loss and unwanted copying in the switching structure, said marking and counting of received cells and counting of cells after switching being performed according to a periodical time frame made of interleaved checking cycles which are grouped by limited and successive series of a same determined number of cycles, each cycle (C 1 ) including a first phase (IC 1 ) for marking and counting the cells as they are received, the identification mark, introduced in every cell received during this first phase, being related to the position of the cycle among the other cycles of the same series, with each first phase of a cycle following immediately the first phase of the preceding cycle, and a second phase (OC 1 ), starting with a determined delay (d 1 ) after the beginning of the first phase of the same cycle, during and after this first phase for a determined duration (t 2 ) and for counting the cells, as soon as switched, which contain the identification mark introduced during the first phase of the same checking cycle, a determination being made at the end of the second phase of each checking cycle of the correspondence between the two counts obtained during the cycle, with a specific signaling as soon as the correspondence as otherwise determined for a cycle is not. obtained.