Layered model for supporting fault isolation and recovery

The primary objective of our research is to efficiently support the manual and automated steps needed to perform network fault management (detection, isolation, and recovery). This paper introduces a layered model and an implementation scheme for enhancing the level of automation in fault isolation and recovery. This complements earlier fault management work that has mostly focussed on automating the fault detection and isolation aspects. Our model allows the use of network information, which is typically available to the network designers, in a form more suitable to the network operators. The model supports the use of fault analysis rules that are defined for the network functions, protocols and services at the various network layers. These rules can capture dependency, availability, redundancy, switchover and hierarchical status information with respect to the network services provided by a network.