This use case represents a more advanced router scenario in which each tenant gets at least one router, and potentially has access to the Networking API to create additional routers. The tenant can create their own networks, potentially uplinking those networks to a router. This model enables tenant-defined, multi-tier applications, with each tier being a separate network behind the router. Because there are multiple routers, tenant subnets can overlap without conflicting, because access to external networks all happens through SNAT or floating IPs. Each router uplink and floating IP is allocated from the external network subnet.
