The server sends updates to each client using unicast.
服务器使用单播向每个客户端发送更新。
To reduce unnecessary traffic, the router forwards the stream via unicast to a specific device instead of flooding the whole network.
为了减少不必要的流量,路由器采用单播把数据流转发给某一台特定设备,而不是向整个网络泛洪。