Specification and Verification of Network Managers for Large Internets

Abstract

Large internet environments are increasing the difficulty of network management. Integrating increasing numbers of autonomous subnetworks (each with an increasing number of hosts) makes it more difficult to determine if the network managers of the subnetworks will interoperate correctly. We propose a high level, formal specification language, NMSL, as an aid in solving this problem. NMSL has two modes of operation, a descriptive mode and a prescriptive mode. In its descriptive mode, NMSL specifies abstractions for the network components and their instantiations, and verifies the consistency of such a specification. The abstractions include the data objects and processes in a network management system. These abstractions are instantiated on network elements. Network elements are grouped together in the specification of domains of administration. An extension mechanism is provided to allow for the specification of new management characteristics that the basic language cannot express. In its prescriptive mode, NMSL generates configuration information directly from a consistent specification. This information is used to configure network management processes to make their operation consistent with their specifications. Standard management protocols (such as the emerging ISO or IETF standards) can be used to incorporate the configuration information into running management processes.