i am doing a project titled "Fault Tolerant Backbone Wide Area Network (WAN) using Cloud Computing and SD-WAN," and l am looking for an expert view and comments on the topic ,as well as thoughts to the following questions ?

1) What are the key advantages and challenges of implementing a fault-tolerant backbone WAN using cloud computing and SD-WAN technologies?

2) How does cloud computing enhance the fault tolerance and resilience of a wide area network infrastructure?

3) What role does SD-WAN play in improving the fault tolerance and performance of a backbone WAN deployed across multiple geographic locations?

4) Are there any specific design considerations or best practices to ensure fault tolerance and high availability in a backbone WAN that relies on cloud computing and SD-WAN?

5) What are some potential security considerations or risks associated with implementing a fault-tolerant backbone WAN using cloud computing and SD-WAN technologies, and how can they be mitigated?