Multicast Routing in Hierarchical Optical Networks Using Collection-Distribution Networks

Emerging optical networks have hierarchical architectures with varying capabilities at different levels. Moreover, many applications nowadays require multicast (one-to-many) connections. We propose a network model that has such a hierarchical architecture which is designed for multicast connections. We develop a multi-stage routing scheme which solves the routing problem in different levels of the network for multicast connections. The network model consists of three levels: collection, core and distribution networks. We adopt the light-trail model in collection-distribution networks which is a convenient way to carry multicast connections. Connection points between the core and collection networks are the edge routers which groom several multicast connections destined to the same distribution network. We evaluate two call acceptance criteria, namely and corresponding to total or partial multicast service, respectively. We show using simulations that our multi-stage routing algorithm with light-trails and edge-grooming improves the performance in the hierarchical network model.