Demonstration of control plane interoperability with integrated optical ports in multi-vendor scenarios

Abstract

Integrated DWDM ports in routers reduce the CAPEX investment, but control plane complexity is increased as the IP router transponder becomes part of the optical domain. This work demonstrates the control plane interoperability between the IP and the optical vendors. Rational behind transponders integration and control plane support Network operators have deployed networks based on IP/MPLS over WSON architectures in their core. This architecture enables cost reduction in comparison with the overhead of legacy architectures like SDH. Following this intention to reduce the network cost, the operators are assessing integrated transponders in packet nodes to deploy in backbone networks. Such colored transponders in the IP cards eliminate the necessity of gray interfaces between the router and the optical gear. Previous work shows that operators can reduce the investment in equipment when doing such port integration. There is a common agreement between operators that data plane integration is a key topic for the network evolution. There are two leading use cases for port integration: metro and core networks. Integrated colored interfaces can be used in metro networks because of the shorter distances and no restoration requirements Some core networks are very simple and do not need the deployment of ROADMs. For these scenarios, the only role of the optical network is to provide point-to-point links. However, large core networks already have GMPLS control plane deployed, which allows the network operators to have automated connection establishment and resilience capabilities. When the transponder is moved from the optical node into the IP node, part of the optical network (transponder) is owned by the IP vendor, while the ROADMS are controlled by an optical vendor. This scenario makes interoperability validation and alignment between vendors crucial. For backbone core scenarios with control plane, the integration of the transponder must not limit the control plane capabilities, not only because automation and resilience is lost in the optical domain, but more important because of the network cost. The customers traffic has to be protected so in case of a failure in the IP or the optical network, the traffic loss is minimum. When there is no optical restoration, the amount of IP cards used for backup purposes is increased. According to our previous findings, the number of IP ports saved thanks to the addition of optical restoration in Telefonica’s Spanish backbone is 37% in 2017. Both arguments (automation and cost) increase the importance of this work. Fig. 1: Experimental set-up for demonstration with integrated ports The paper outlines the control plane architecture for the integrated port case. Next, the control plane extensions required to support the integrated ports are presented. Finally, the experimental set-up is explained and the tests are shown. Control plane architecture with integrated