Hi Bobby,DWDM: Multiplex multiple signals on single optical fiber using different wavelength.DWDM lines have redundant protection. We use different hub sites as interconnection nodes to form DWDM protection loops with each other. The nodes of redundant protection are between each hub of HKBN.DWDM redundant protection loop architecture: Note: The figure shows dual DWDM loops. When a single loop A is interrupted and causes a failure, we can ensure that data can have another loop B to reach the customer's office.The attachment provides the SLA of the DWDM service, please refer to it.In addition,1. It is recommended that customers purchase and configure their own routers in the local office.2. AWS cloud virtual routers and services require customers to apply on AWS Cloud.