Abstract: The device for access control between ATM networks, comprises signaling analysis means (4) and traffic analysis means (20, 21) linked to an ATM switch (3) configured so as to steer via the signaling analysis means, ATM signaling messages exchanged between internal and external ATM networks, and so as to steer via the traffic analysis means, traffic-bearing ATM cells exchanged between the internal and external networks within the framework of ATM connections established by means of said ATM signaling messages. Access control management means (7) dynamically configure the traffic analysis means (20, 21) as a function of an access control policy and of information gathered by the signaling analysis means (4) in such a way that the traffic analysis means filter each ATM cell in accordance with the access control policy.

Abstract: A system and a process arranges equitable-loss data packets in a high-volume asynchronous transfer mode (ATM) system and establishes the output order of the packets. There are a plurality of inflowing data packet streams, a minimum quantity ri of each incoming flow being reserved. At all times, there is a ratio K(t) between two parts of each incoming data packet flow. One part is a quantity of packets &Dgr;xi(t) allocated above the minimum reserve quantity ri. The other part ei(t) is an instantaneous quantity &Dgr;xi(t) above the minimum reserve quantity ri.

Abstract: The invention provides a method of verifying the integrity of sequences of data transmitted from a first station to a second station in a broadcast network during a call set up between the first and second stations. First and second encipherment seals are calculated in a control station separate from and independent of the first and second stations, respectively in response to reception of a sequence corresponding to the transmitted data sequence and in response to reception of the sequence which is received in and retransmitted by the second station. A comparison of the calculated seals for integrity verification is preceded in the control station by searching for the first seal calculated according to an identification word of the sequence which is retransmitted by the second station. The invention relates to a method of verifying the integrity of data sequences exchanged between stations respectively belonging to different broadcast networks.

Abstract: In a message transmission network of CSMA-CD type, each station is connected by a coupler to the common transmission channel. One or more indices is allocated to each coupler; and each coupler is provided with an automatic device capable of establishing a predetermined sequence of index sub-sets, such as a dichotomous tree. A counter of period E progresses at the rate of the end of channel phase orders. The coupler freely transmits only if its count E is at zero. When a collision appears in this state, the counter E starts from a chosen forced state, and all the couplers put their automatic devices into action, which also progress at the rate of the ends of channel phases, to establish sub-sets of said sequence and to determine, by comparison of their own indices with said sub-sets, whether they have in any given channel phase again obtained the right to transmit on said common channel. The couplers will subsequently be able to transmit one by one without collision.

Abstract: The invention relates to a variable pitch conveyor or a chain in which the length of the links can be varied.Each link includes a cross-bar T.sub.i mounted between longitudinal rocking bars B.sub.i that are interconnected by linked bars L.sub.i. The bars B.sub.i are integral with a toothed sector which controls the rocking of the bars by meshing with a moving rack adapted to follow, with a variable speed, the motion of the chain.