Joint Optimization Of Routing and Flexible Ethernet Assignment In Multi-layer Multi-domain Networks

Optimized routing in multi-layer multi-domain (MLMD) IP-optical networks is challenging due to different technologies and policies in different domains. In this paper, we investigate the problem of using the hierarchical path computation engine (PCE) to leverage the performance of FlexE-the new flexible Ethernet technology which is used to map traffic between different layers and different domains. Our proposed PCE can be implemented in MLMD orchestration platforms to optimize network utilization while meeting delay constraints. We formulate the optimization problems of traffic routing and physical slot assignment for both FlexE-Aware and FlexE-Unaware modes with respect to QoS requirements, intra-domain information privacy and FlexE constraints. To solve the problem, we propose new algorithms that jointly optimize the routing and FlexE client assignment in polynomial time. To deal with the issue of missing intra-domain information, we use a novel implicit routing strategy to collect the intra-domain information from the child PCEs. Simulation results show the proposed solution achieves 90.1% higher efficiency than the state-of-the-art solutions.