Managing groups in dynamic networks

Traditionally networks are structured for operation in quite a static manner. Even if routing protocols support flexible and self-organizing networks, other configurative tasks like forming LAN segments on (OSI) layer two and subnets on layer three as well as most application-specific configuration are not intended to be frequently modified. Reorganizing them therefore often requires larger management efforts. In recent years several technologies such as virtual LAN, configuration boot-strapping and directory protocols have evolved to allow the implementation of dynamic configuration in the networking and computing infrastructure that in turn can support the dynamics needed for nomadic computing and frequently changing, flexible organisational structures. Each of these technologies defines groups at a different layer. This leads to new requirements for integrated management solutions covering all networking, system and application entities and motivates the necessity of a new kind of more generic tool. We derive user requirements starting from a concrete scenario which demonstrates the various needs for defining groups of resources in a dynamic and flexible manner. After investigating some emerging technologies, with respect to their grouping aspects, e.g., related to the frequency of changes, multitude and layering of groups, we focus on the idea of a generic group object model as an important management abstraction. The motivation of this abstraction is supported by its application to event correlation and fault diagnosis and for policy-based configuration management, especially in support of nomadic computing