Middleware and Management Support for Programmable QoS-Network Architectures
Hermann de Meer · 2001
This paper focuses on management and middleware support for incremental updating of code and policies on various levels of granularity in time and space and on code deployment in vastly large distributed systems such as a networking infrastructure. In particular, we describe a middleware for programmable Di#erentiated Service (Di#Serv) architectures. Di#Serv architectures are envisaged by the standardization body of the IETF to be open to an evolutionary process and to facilitate adjustments to local conditions. The middleware we suggest for enabling openness and programmability of future Di#Serv QoS architectures uses XML in the definition of specific policy languages, provides XML extensions to satisfy new needs and the management of deployed policies on di#erent active nodes. Based on our middleware, router packet forwarding policies may be flexibly defined and, in an extreme case, even dynamically updated at run-time on the active nodes as a function of the network/router status. Based on a two-level language approach, the middleware decouples policy management, which is handled through XML interpretation, from packet forwarding that is implemented in more e#cient languages. The two-level language approach allows a compilation of highly e#cient executable code from an intermediate XML virtual machine level representation. 1