摘要 |
In a best effort type service of an ATM communication network for circulating an RM cell, a subscriber's switchboard holds the latest route information, and the RM cell is used for short distance communication bewtween the communication terminal and subscriber's switchboard. For a plurality of connections accommodated in the switchboard and using a transmission line or a route in common, information on the allowable transmission rate, the actual transmission rate, the full bandwidth and full input bandwidth of the transmission line or the route, and the number of connections using in common the transmission line are collected and held. A transmission rate acceptable for the caller's terminal is calculated for each connection on the basis of the information. An increase of a memory capacity is restricted by providing a common buffer and managing it by a pointer value. A list of cells which have arrived simultaneously is prepared, and is managed by the pointer value. The cells are sent out at different timings so as not to be discarded. Even when congestion is solved, the restriction is not quickly lifted but control is effected in consideration of the increment of the cell flow rate immediately after the lift. Convolution calculation is made only once for determining the overall mean cell loss ratio and consequently the amount of calculation is reduced. <IMAGE> |