The computer network interview questions: OSI seven-layer network model and related protocols

First, the application layer

　　Function: provides services for applications and provides for the application of the relevant details of the communication;

　　Comprising the following protocol:

　　1, hypertext transfer protocol HTTP: This is a basic access protocol client / server; browser sends a request to the server, and the server will be the appropriate page.

　　2, hypertext transfer protocol FTP: to provide interactive access, based on client-server model, connection-oriented, reliable transport service using TCP

　　　　The main function: to reduce / eliminate the incompatibility under different operating system files

　　3, remote login protocol TELNET: client-server model, able to adapt to the differences in many computers and operating systems, network virtual terminal NVT meaning of

　　4、