NESTOR: an architecture for network self-management andorganization

摘要

Configuration management presently requires complexnlabor-intensive processes by experts. A single configurationntask-installing/reconfiguring a system, or provisioning anservice-typically involves a large number of activities fragmented amongnmultiple network elements, each with its own proprietary configurationnmanagement instrumentation and tools. A change may cause configurationninconsistencies resulting in failures or inefficiencies; undoing changesnto recover an operational state is often very difficult or evennpractically impossible. Therefore, configuration management is veryncostly, error prone, and often results in unpredictable failures andncostly recovery. NESTOR seeks to replace labor-intensive configurationnmanagement with one that is automated and software-intensive.nConfiguration management is automated by policy scripts that access andnmanipulate respective network elements via a resource directory servern(RDS). RDS provides a uniform object-relationship model of networknresources and represents consistency in terms of constraints; itnsupports atomicity and recovery of configuration change transactions,nand mechanisms to assure consistency through changes. RDS pushesnconfiguration changes to network elements using a layer of adapters thatntranslate operations on its object-relationship model to actions onnrespective elements. NESTOR has been implemented in two complementarynversions and is now being applied to automate several configurationnmanagement scenarios of increasing complexity, with encouraging results