Switching of redundant communication channels in ATM switching system

Abstract

An ATM switching system comprises a redundant communication; system consisting of act-system and standby-system communication channels. Cells are sent through both the communication channels. A switch element is provided for performing system switching from the act-system communication channel to the standby-system communication channel in response to a request-to-switch. The switch element is connected with a line concentrator. The ATM switching system further comprises reading and controlling elements functionally realized installed software, for example. The reading element reads, when receiving the request-to switch, a number of the cell passing the line concentrator channel by channel. And the controlling element controls a switching operation of the switch element based on the read numbers. By way of example, the controlling element is formed such that it calculates a difference between the read numbers, allows the switch element to perform the switching operation when the difference is less than a specified value, and prohibits the switch element from the switching operation when the difference is not less than the specified value. By this, such service interruption as cell losses during the redundant system switching can be avoided, providing a stable and reliable cell communication.

Dependencies are inferred from the claim text.