FELL: A Flexible Virtual Network Embedding Algorithm with Guaranteed Load Balancing

Network virtualization has emerged as the most promising approach to overcome the current ossification of the Internet. A key problem in it is how to efficiently and effectively make use of substrate network resources by embedding multiple virtual networks with various constraints. Due to its NP-hardness, many heuristic approaches have been proposed. However, most of them restricted the solution space at the expense of limiting practical applicability and did not consider response time requirements or load balancing. In this paper, we propose FELL, a Flexible virtual network Embedding algorithm with guaranteed Load baLancing for the general problem. Based on simulated annealing, FELL can flexibly control the tradeoff between results accuracy and running time to meet various requirements of different applications by changing parameters. A novel cost criterion that reflects the impact of distribution of allocated resources for an embedding is designed to guarantee load balancing, which enables substrate network to avoid resource fragmentation. Path splitting is supported to achieve better resource utilization by making use of small pieces of available bandwidth. We also design some key functions including generating initial and neighbor solutions. The effectiveness of our algorithm is finally validated by our simulations.