ATM exchange for monitoring congestion and allocating and transmitting bandwidth-guaranteed and non-bandwidth-guaranteed connection calls

摘要

PCT No. PCT/JP94/01199 Sec. 371 Date Apr. 13, 1995 Sec. 102(e) Date Apr. 13, 1995 PCT Filed Jul. 21, 1994 PCT Pub. No. WO95/03657 PCT Pub. Date Feb. 2, 1995An ATM including both a bandwidth-guaranteed connection call and a non-bandwidth-guaranteed connection call together, with respect to the bandwidth-guaranteed connection call, a scheduler 21 allocates the number of time slots which correspond to a required bandwidth to the bandwidth-guaranteed connection call from among the N time slots which constitute one period and so controls as to transmit an ATM cell at an allocated time slot. A non-bandwidth-guaranteed cell transmitting element 31 transmits an ATM cell of a non-bandwidth-guaranteed connection call at a time slot which is not allocated at any bandwidth-guaranteed connection call. A congestion/normal state monitoring element 121 sets in advance a queue length which is regarded as the occurrence of a long-term congestion in a queuing buffer 111, and compares the actual queue length with the preset queue length so as to detect the occurrence of a long-term congestion.