OSPF for Implementing Self-adaptive Routing in Autonomic Networks: A Case Study

Abstract

Autonomicity, realized through control-loop structures operating within network devices and the network as a whole, is an enabler for advanced and enriched self-manageability of network devices and networks. In this paper, we argue that the degree of self-management and self-adaptation embedded by design into existing protocols needs to be well understood before one can enhance or integrate such protocols into self-managing network architectures that exhibit more advanced autonomic behaviors. We justify this claim through an illustrative case study: we show that the well-known and extensively used intra-domain IP routing protocol, OSPF, is itself a quite capable self-managing entity, complete with all the basic components of an autonomic networking element like embedded control-loops, decision-making modules, distributed knowledge repositories, etc. We describe these components in detail, concentrating on the numerous control-loops inherent to OSPF, and discuss how some of the control-loops can be enriched with external decision making logics to implement a truly self-adapting routing functionality.