This guide assumes that the remote site (side office) is already in place with its application and FortiGate instances as the diagram shows. Therefore, this guide does not cover the steps for their deployment.
The remote site or side office is where customer workloads are present. This can be an on-premise or cloud deployment.
With an SD-WAN transit routing setup with Google Network Connectivity Center (NCC), you can route data and exchange border gateway protocol (BGP) routing information between two or more remote sites via GCP.
You can do this by configuring the NCC hub and an endpoint (spoke) for each remote site. To reduce network latency, you deploy a spoke in the GCP region that is located geographically closest to the remote site for which you created the spoke. The NCC hub itself is VPC-specific.