Ensuring data consistency in large network systems

Data management in network systems is different from that in traditional data systems. It is important to ensure data consistency not only between network management systems but also between network elements, which may not support database protocols such as two-phase commit, as well as between network management systems and network elements. The problem is non-trivial, especially when data are updated unilaterally from network elements without notifying network management systems, as network management systems and network elements operate independently and autonomously. This paper presents a technique that maintains data consistency in large network systems. The technique consists of a suit of protocols that allows the creation, deletion and modification, as well as downloading of data to network elements and verification of data consistency between management systems and network elements. Together, these protocols ensure consistency when data are not updated directly from network elements, and otherwise detect and resolve inconsistencies as long as the updated data have not been used by network elements for configuration.