Performance improvement of an optical network providing services based on multicast

Operators of networks covering large areas are confronted with demands from some of their customers who are virtual service providers. These providers may call for the connectivity service which fulfils the specificity of their services, for instance a multicast transition with allocated bandwidth. On the other hand, network operators want to make profit by trading the connectivity service of requested quality to their customers and to limit their infrastructure investments (or do not invest anything at all). We focus on circuit switching optical networks and work on repetitive multicast demands whose source and destinations are {\em \`a priori} known by an operator. He may therefore have corresponding trees "ready to be allocated" and adapt his network infrastructure according to these recurrent transmissions. This adjustment consists in setting available branching routers in the selected nodes of a predefined tree. The branching nodes are opto-electronic nodes which are able to duplicate data and retransmit it in several directions. These nodes are, however, more expensive and more energy consuming than transparent ones. In this paper we are interested in the choice of nodes of a multicast tree where the limited number of branching routers should be located in order to minimize the amount of required bandwidth. After formally stating the problem we solve it by proposing a polynomial algorithm whose optimality we prove. We perform exhaustive computations to show an operator gain obtained by using our algorithm. These computations are made for different methods of the multicast tree construction. We conclude by giving dimensioning guidelines and outline our further work.Comment: 16 pages, 13 figures, extended version from Conference ISCIS 201

Automatic Network Services Aligned with Grid Application Requirements in CARRIOCAS Project

ISBN : 978-3-642-02080-3 / ISSN : 1867-8211International audienceAutomatic Service framework named Scheduling, Reconfiguration and Virtualization (SRV) is developed in CARRIOCAS project to enhance existing Telecom network infrastructures for supporting grid applications sharing IT resources interconnected with ultra-high performance optical networks. From the requirements of Grid applications a classification is pro po sed to specify the network services and their attributes. In large-scale collaborative environments, SRV solution is described to enable automatic network service operations according to high-performance computing service access. The resources hosted at datacenters are virtualized to be attached to transport network infrastructure offering uniform interfaces towards external cus tomers. New level of service bindings is defined with network services du ring executions of Grid applications' workflows. On-demand intensive com puting and visualization services scenario is described in Telecom environment