Patent ID: 7420926

Claim:
A method for locating a faulty module in a packet handling device in a telecommunication network, the device having a data path for carrying data packets, the data path passing through a plurality of modules in the device, the method comprising: a) at a plurality of locations on the data path within the device reading an integrity verification code from a data packet and determining if the integrity verification code matches the data packet; and, b) if the integrity verification code at one of the locations does not match the data packet, generating a signal indicating that the data packet is corrupted wherein the device includes a plurality of replaceable modules on the data path and the method comprises: determining if the integrity verification code matches the packet at an egress of each of the replaceable modules; determining if the integrity verification code matches the packet at an ingress of each of the replaceable modules; and identifying as faulty one of the replaceable modules for which it is determined that the integrity verification code does match the packet at the ingress of the replaceable module but does not match the packet at the egress of the replaceable module.