Multi-layer Resilience in Deutsche Telekom’s IP Core and Aggregation Network

Abstract:
This paper considers cost savings that can be achieved by a multi-layer (ML) dimensioning and interworking within a practical packet-optical backbone network. They are based on several multi-layer resilience (MLR) schemes. This includes optical restoration against optical failures (MLR-O) and spare backup interfaces, provisioned against port failures (MLR-P). The design steps comprise an ML router bypass optimization (MLBO) of 100Gbit/s wavelengths through an agile photonic layer equipped with colorless-directionless ROADM. In order to minimize costs, dedicated L1/L2 (ODU or Ethernet) switching devices will not be deployed. We apply this methodology to DT’s IP backbone, showing about 25-30% fewer interfaces are required. The total cost saving potential is estimated by using today’s average market prices, proving the superiority of the approach. Finally, we extend MLR to the aggregation network with its typically ring-like topologies.