Optimized design of survivable MPLS over optical transport networks

Abstract

-In this paper we study different options for the survivability implementation in MPLS over Optical Transport Networks (OTN) in terms of network resource usage and configuration cost. We investigate two approaches to the survivability deployment: single layer and multilayer survivability and present various methods for spare capacity allocation (SCA) to reroute disrupted traffic.The comparative analysis shows the influence of the traffic granularity on the survivability cost: for high bandwidth LSPs, close to the optical channel capacity, the multilayer survivability outperforms the single layer one, whereas for low bandwidth LSPs the single layer survivability is more cost-efficient. For the multilayer survivability we demonstrate that by mapping efficiently the spare capacity of the MPLS layer onto the resources of the optical layer one can achieve up to 22% savings in the total configuration cost and up to 37% in the optical layer cost. Further savings (up to 9 %) in the wavelength use can be obtained with the integrated approach to network configuration over the sequential one, however, at the increase in the optimization problem complexity. These results are based on a cost model with actual technology pricing and were obtained for networks targeted to a nationwide coverage.

Resilient network design: challenges and future directions

“…However in recent years there has been increasing interest in network resilience and survivability with journals dedicating special issues to the resilience of networks and components, specialized focused conferences being held (e.g., Reliable Network Design and Modeling (RNDM), Design of Reliable Communication Networks (DRCN)) and several excellent books published [26,33,42]. The current literature tends to focus on providing survivability in a particular technology at a specific layer (i.e., application overlay layer [21,36] switched layer (IP [18], MPLS [4]), physical transport layer [25]) in a piece of the network architecture (e.g., MAN or WAN). For example, developing techniques for implementation of lightpath restoration in core DWDM optical backbone sections of the Internet (e.g., a Tier 1 ISP network) [25] or survivable SONET Ring techniques to overcome link failures in MANs.…”