Q:Describe one type of secondary devices in detail

A:The secondary device that I would describe is the router

The router, which is a device connected to the LAN and wan of the Internet, automatically selects and sets the route according to the channel condition, sending the signal in the best way and in the order before and after.

The router is the hub of the Internet, the traffic police.

The router has been widely used in all walks of life, a variety of different grades of products has become the backbone internal connection, backbone network and backbone network and Internet connectivity between the main force of business.

The main difference between routing and switching is that switches occur on the second layer of the OSI reference model (the data link layer), while routing occurs on the third layer, the network layer.

This difference determines that routing and switching need to use different control information in the process of mobile information, so the way to realize their respective functions is different.

Routers or gateway devices are used to connect multiple logically separate networks that represent a single network or subnet.

When data is transferred from one subnet to another, it can be done by routing the router.

Routers have judgment, therefore, chose the path of an IP address and network function, it can in networking environment, more flexible connections, can use different data group and medium access method connected subnet, the router will only accept information source station or other routers, belong to the network layer of an Internet device.