A modular notation for monitoring network systems

Abstract

Design of next generation network systems with predictable behavior in all situations poses a significant challenge. Monitoring of events happening at different points in a distributed environment can detect the occurrence of events that indicates significant error conditions. We use Modular Timing Diagrams (MTD) as a specification language to describe these error conditions. MTD's are a component-oriented and compositional notation. We take advantage of these features of MTD and point out that, in many cases, global MTD specifications describing behaviors of several system component can be efficiently decomposed into a set of sub-specifications. Each of the sub-specifications describes a local monitor that is specific to the component on which the monitor is intended to run. We illustrate the compositional nature of MTD in describing several network monitoring conditions related to network security.