2.1.5 Computer network protocol: TCP/IP

0. Application phase: You open the browser, enter the URL column in the browser, press [Enter]. At this point, the URL column and related data will be wrapped into a browser data, and down to the TCP/IP application layer;
1. Application layer: The HTTP communication protocol provided by the application layer, the data from the browser is reported, and given an application layer header, and then dropped to the transport layer;
2. Transport layer: Because HTTP is reliable online, the data is dropped into a TCP packet, and a TCP packet header is given to the network layer;
3. Network layer: The TCP package into the IP packet, and then give an IP header (mainly the source and destination IP), to the link layer dropped;
4. Link layer: When using the Ethernet network, IP will be wrapped to the Mac frame according to CSMA/CD Standard, and give the MAC header, and then turn into a bit string, transfer media to the remote host.

2.1.5 Computer network protocol: TCP/IP