Abstract: A method for the insertion of a flow of applications-specific cells or maintenance cells into a flow of incident cells according to the ATM standard or a similar standard. To this end, a message characterizing each received cell is formed in real time. This message gives, among others, a piece of information on the type of cell, and the user cells are selected so that each of them is stored for the period of time in which a processing operation is performed on the stored cells. This processing operation is done on the basis of the messages formed to generate a specific cell (or a maintenance cell). This cell is sent out whenever a determined number of user cells has been sent out, and a vacant cell is eliminated. Else, a pending user cell is sent out and a vacant cell is generated. Application to transmission on the ATM networks.

Abstract: An apparatus for testing an ATM type telecommunications network and for measuring the performance of connections of the network, the network conveying information elements in the form of cells according to the ATM standard. To this end, the apparatus includes a transmitter provided with a set for the preparation of the physical layer and a set for the preparation of the ATM transport layer organized into virtual paths and virtual channels (VP/VC), a receiver provided with a set for the processing of the signals of the physical layer and a set for the processing of the flow of cells of the ATM transport layer. Application to telecommunications in ATM mode.

Abstract: A method for the measurement of performance parameters of an asynchronous transfer mode transmission network having an asynchronous transfer mode channel, the method including: generating identifiable measurement cells and inserting the identifiable measurement cells into an asynchronous incident flow transmitted by the asynchronous transfer mode channel; receiving an asynchronous flow of cells from the channel, counting a total number of cells received in the asynchronous flow, detecting the identifiable measurement cells among the asynchronous flow and counting a total number of identifiable measurement cells received in the asynchronous flow, comparing a content of each individual identifiable measurement cell with an expected content for that individual identifiable measurement cell so as to detect transmission errors, generating and memorizing a counting information element upon each reception of a given number of cells in the asynchronous flow, the counting information element comprising the total numbe

Abstract: A process for monitoring a network which conforms to an Asynchronous Transfer Mode process standard including reading conveyed cells at a point (P) in the network (R), performing a preprocessing step which includes reformatting cells that have been read, selecting cells that are useful for execution of testing operations, recalculating at least a portion of check information, and arranging the recalculated check information and the received check information into messages, processing the messages in order to verify the coherence between the recalculated check information and the received check information.

Abstract: An equipment embodying the invention is designed for bit-level quality check of a digital link in the presence of real traffic. The equipment complies with CCITT recommendations and comprises two checking stations (SP, SS) respectively located at two ends of the digital link (LT) and connected to one another by a service link (LS). First and second check information relating respectively to groups of transmitted frames (MTn.sub.p) and to groups of received frames (MTn.sub.s) are calculated in the stations and comparisons are made in order to detect the transmission errors. The check informations and the frame groups concerned by the transmission errors are transmitted from one station to the other via the service link. Processing circuits are distributed among the stations thereby processing the frame groups concerned by the transmission errors, i.e., analyzing at bit level the errors in the erroneous frames and deriving statistical information and recordings relating to said errors.