3.Internet主机才能使用Internet吗? 总答案 恰恰相反,当前大多数PC并不是作为Internet主机连接于Internet,而是以1级或2级的连接形式连接到Internet。下面介绍Internet的3种连接级别。 1级连接:通过网关访问Internet 在这种情况下,PC所在的较小网络不属于Internet网的一部分,该网与Internet网之间有一个网关,以实现两网之间的数据交换。但网关通常只允许两网间进行电子邮件的交换,还可能允许利用电子邮件协传输小文件。网关通常不支持处理层/应用 3.Internet host to use the Internet? The overall answer is exactly the opposite, most of the current PC is not connected to the Internet as an Internet host, but to 1 or 2 connections to connect to the Internet. Here are three Internet connection levels. Level 1 Connection: Accessing the Internet through a Gateway In this case, the smaller network where the PC is located is not part of the Internet, and there is a gateway between the network and the Internet to allow for the exchange of data between the two networks. However, gateways usually only allow the exchange of e-mail between two networks and may also allow the use of e-mail to transfer small files. Gateways usually do not support processing layers / applications