大规模的BGP网络为什么需要使用BGP Route Reflectors

By default, Calico advertises routes using the BGP Protocol with a full node-to-node mesh. Every node peers to every other node to broadcast routes which tends to no longer be scalable beyond 200 nodes. Konvoy has support for Calico in-cluster BGP Route Reflectors. We recommend configuring them on clusters with more than 100 nodes. When Route Reflector nodes are configured, the full mesh mode is disabled and each node connects only to in-cluster Route Reflectors. This reduces CPU and memory utilization on worker and control-plane nodes.

超过100节点，建议部署 Route Reflectors，原理是什么？