Performance analysis of harmony: An optical, multi-domain network resource broker

Harmony is a network resource brokering system that provides co-allocation of heterogeneous (optical) network resources in multi-domain and multi-technology environments with advance reservation functionalities. This system is one of the outcomes of the Phosphorus EC FP6 research project. The Harmony system architecture has evolved from a first proof-of-concept, centralized network service plane (NSP) to a distributed NSP model; passing through a mid-term, multi-level hierarchical model. This paper addresses key performance and scalability topics of the Harmony system, analyzing its functional architecture under different scenarios, and given different request distribution patterns. The study analyzes and evaluates whether the system can scale to scenarios that accept more requests per second or control more administrative domains. Thus, analysis results are discussed in order to determine why the distributed architecture with flexible, in time and bandwidth, advance reservation functionalities has better performance, scalability and convergence when increasing the service plane entities and their relationships.