Intelligent shared-segment protection

Progress in network technologies and protocols is paving the road towards flexible optical transport networks, in which dynamic leasable circuits could be set up and released on a short-term basis according to customers’ requirements. Recently, new solutions for automatized network management promise to allow customers to specify the terms of the service level agreement (SLA) to be guaranteed (with different price range) by the service provider. In this paper we consider that these service level specifications (SLS), since they are now made available on-demand during the connection request, could be exploited to retrieve useful information able to improve the routing efficiency. In particular, we propose to exploit the knowledge of connection holding time, among the other SLS, to develop a novel intelligent approach for shared-segment protection (SSP). We will exploit the knowledge of the holding-time of connection requests to minimize resource overbuild due to backup capacity and hence to achieve resource-usage efficiency. For a typical US nationwide network, we compare our two proposed holding-time aware approaches to the respective two holding-time-unaware approaches: both of them, even in their holding-time unaware version, have been shown to be very efficient solutions for shared-segment protection. Nonetheless, we have obtained additional savings on resource overbuild of up to 11% for practical scenarios exploiting holding-time knowledge. 2008 Published by Elsevier B.V.