Using Topology Aggregation for Efficient Shared Segment Protection Solutions in Multi-Domain Networks

The dynamic routing problem for Overlapping Segment Shared Protection (OSSP) in multi-domain networks has not received a lot of interest so far as it is more complex than in single-domain networks. Difficulties lie in the lack of complete and global knowledge about network topologies and bandwidth allocation whereas this knowledge is easily available in single-domain networks. We propose a two-step routing approach for the OSSP based on a topology aggregation scheme and link cost estimation: an inter-domain step and an intra-domain step. We propose two different heuristics, GROS and DYPOS for the inter-domain step, and a "Blocking-go-back" strategy in order to reduce the blocking rate in the intra-domain step. We compare the performance of the two heuristics against an optimal single-domain approach. We show that both heuristics lead to resource efficient solutions that are not far from the optimal ones. Moreover, both heuristics require relatively small computational efforts and are scalable for multi-domain networks.