Circuit switching establishes a dedicated physical connection for voice or data between a sender and receiver 电路交换为声音或资料在传送端和接收端之间建立一个了专用的实体连接。
2.
Routers determine the destination of the data from the network layer headers and transfer the packets to the appropriate data link connection for delivery on the physical connection 路由器决定来自网路层表头的资料的方向及在实体连接上转送封包到适当的资料链路连线。
