| 摘要 |
A billing scheme for a telecommunications network is described in which a billing record for a call including at least a plurality of data bytes is generated in a switch (10), each billing record is duplicated, and check information is generated from each data byte of a billing record and associated with each said data byte to form a protected billing record. Each protected billing record of a duplicated pair is transmitted via two independent transmission lines to processing means (40, 50) in which the associated check information is generated byte-for byte from each received billing record and the generated check information is compared byte-for-byte with the transmitted check information in parity checking circuits (60, 61). If for any one byte of a billing record, the generated check information does not agree with the received check information, that billing record is discarded. If there is no inconsistency between the received and generated check information for both billing records of a duplicated pair, the two billing records of the pair are compared bit-for-bit in a comparator (70). If any difference is found between the billing records of the pair, both billing records are discarded. Otherwise the received billing records are stored in non-volatile memory (75). <IMAGE> |
