A fault-tolerant MPLS-based control and communication network for the Lucent LambdaRouter

Recently, the importance of out-of-band signaling has been realized for next-generation intelligent optical transport networks (OTNs). This next-generation OTN will be capable of providing services like real-time point-and-click provisioning of optical channels, automatic protection and restoration, network topology auto-discovery, and bandwidth management. However, for successful deployment and usage of these services, reliability of the out-of-band signaling network, referred to as the control and communication network (CCN), is critical. Specifically, it is desired that the signaling network transparently recover from any single failure events and continue providing communication between OTN nodes. In this paper, we propose a fault-tolerant, scalable, and cost-effective architecture for IP-based control plane of next-generation OTNs. The architecture is based on multiprotocol label switching (MPLS) protocols. The essence is to provide diverse paths in the network so that any failure in the OTN, as well as the control network, can be recovered transparently. These diverse paths employ a packet dual-feed and select mechanism for fast recovery from failures. The architecture requires diverse paths between the neighboring OTN nodes, instead of all-pair of nodes, enabling the control plane to seamlessly scale with the size of the OTN network. Moreover, the architecture allows the control plane topology to be independent of the OTN topology. This gives operators considerable flexibility in the design of the CCN in a cost-effective manner by using virtual private networks (VPNs) through public data networks, or by avoiding unnecessary OTN links. We also present an implementation of the proposed architecture that will be used as the highly reliable IP-based CCN in OTNs consisting of the Lucent LambdaRouter, an optical cross-connect product. Although in this paper the architecture is discussed in the context of providing a highly reliable IP-centric CCN for optical cross-connect-based (OXC-based) OTNs, it can be extended to a general purpose fault-tolerant CCN for any next-generation OTN.3