Silent datapath failure detection

摘要

The apparatus and method herein provide a means for actively monitoring a communications node for datapath disruptions caused within the node. It was developed to address linecard failures that were detected in the field and for which traditional error detection mechanisms such as CRC and OAM CC checks are not feasible. According to one implementation, statistics are collected over a preset time interval. If any egress cell counts are zero over a full interval, then the ingress interface for that datapath is determined, e.g. using the node's cross-datapath information, and the corresponding linecard of that ingress interface is contacted to determine the ingress cell count. If the ingress cell count is non-zero then the datapath is alarmed since the complete lack of cells transmitted at the egress indicates a datapath disruption. Other implementations that can detect datapath disruptions without a complete interval of statistics collection and which do not require a zero egress cell count are possible for cases where congestion, linecard resets, etc. can be ruled out.