Patent ID: 6522652
Filing Date: 2003-02-18
Classification: H04L

Abstract:
An ATM exchange comprising:a VPI/VCI converter for retrieving a logic value according to an input VPI/VCI value written in a VPI/VCI field of header information of a cell arriving to an input port of the ATM exchange, said logic value being predetermined for each of individual connections to be dealt with individually and groups of connections to be dealt with collectively by the ATM exchange; a mask-bit generator for generating a mask-bit pattern having the same bit length with the VPI/VCI field, a number, which is predetermined for each of the groups of connections, of lower bits of the mask-bit pattern having logic â€˜1â€™ and other upper bits thereof having logic â€˜0â€™ when the mask-bit pattern concerns one of the groups of connections, and all bits of the mask-bit pattern having logic â€˜0â€™ when the mask-bit pattern concerns one of the individual connections; and a VPI/VCI bit selector for generating an output VPI/VCI value to be written in the VPI/VCI field of the cell before the cell is transmitted from an output port of the ATM exchange, by selecting logic of each bit of the output VPI/VCI value to have the same logic with a corresponding bit of the logic value out-putted from the VPI/VCI converter when a corresponding bit of the mask-bit pattern has logic â€˜0â€™, and to have the same logic with a corresponding bit of the input VPI/VCI value when a corresponding bit of the mask-bit pattern has logic â€˜1â€™.