US Patent 7130261 Hierarchical dependability for open distributed environments

Systems and methods that are operable in open distributed environments, such as ToL and other similar systems are described. One dependability system includes a hierarchical arrangement of two or more nodes each having a fault analyzer object programmed to respond to status information relating to an associated system of one or more objects based upon a respective set of policies designed to improve object availability. The dependability system may be implemented in a telephony system. The telephony system may include a packet switched network, a gatekeeper coupled to the packet switched network, and a server coupled to the packet switched network and configured to process telephone calls over the packet switched network. A dependability method that is implemented in a distributed packet switched network also is described. In accordance with this method, status information relating to one or more component objects of a node in a hierarchical arrangement of two or more nodes is received at a lower-level node. In response to the received status information a component object control instruction for controlling the operational state of one of the component objects is issued at the lower-level node based upon a respective set of policies designed to improve object availability. A status report is issued from the lower-level node to a higher-level node in the hierarchical arrangement of nodes.