Supporting dynamic bandwidth adjustment based on virtual transport link in software-defined IP over optical networks

Packet and optical networks are managed independently in both current carrier networks and datacenter interconnection networks, which results in a lack of service agility and is a significant source of capital expenditure and operating expense overhead for the network operator. In our previous works, we have proposed and experimentally demonstrated a software-defined networking- based architecture (service-aware architecture) for converged control of packet and optical networks. In this paper, we first propose a concept called virtual transport link (VTL) to support dynamic link aggregation in software- defined IP over optical networks. Then, the VTL-based dynamic bandwidth adjustment (VTL-DBA) method is proposed for improving the resource utilization and for simplifying service provisioning. The feasibility of our proposals is experimentally verified on our software-defined IP over optical networks testbed. The performance of the VTL-DBA method is also evaluated based on our simulation platform in terms of resource usage, resource utilization, and blocking probability. For carrying quality guaranteed services, VTL-DBA saves 25% of transport resources on average compared with static bandwidth allocation methods, and it shows an increase of 15% in the average resource utilization. For carrying both quality guaranteed services and quality tolerant services, VTL-DBA reduces the service blocking probability to only 10% on average with higher resource utilization than static bandwidth allocation methods.