Patent ID: 6765874
Filing Date: 2004-07-20
Classification: H04L,H04Q

Abstract:
A method of measuring the duration of a service disruption event in an asynchronous transfer mode (ATM) data transmission channel, using a data analyzer that has both a disruption timer and a guard timer, the method comprising the steps of:a) providing an ATM stream of data into the data transmission channel, the data comprising a stream of identifiable data cells in a defined order; b) detecting with a data analyzer the stream of data after transmission through the data transmission channel in order to determine whether or not any of the data cells have been corrupted in transmission through the data transmission channel; c) disrupting the transmission of the stream of data through the data transmission channel so that at least some of the cells are corrupted; d) using the disruption timer to time the service disruption event when a first corrupted data cell is detected by the data analyzer; e) using the guard timer to time a guard time interval when a subsequent data cell that is not corrupted is detected by the data analyzer whilst continuing to use the disruption timer to time the service disruption event; and then either f) resetting the guard timer if the data analyzer has detected a further corrupted data cell prior to the guard timer timing a predetermined guard time; or g) determining the duration of the service disruption event from the disruption timer when the guard timer has timed the predetermined guard time.