Questions of computer network face questions _ face

1.TCP and UDP differences and their respective characteristics

Connection-oriented TCP

TCP is connection-oriented, so the handshake consumes resources, reliable connections, no data loss, suitable for large amount of data exchange
"Connection-oriented" is the need to establish a connection with each other before formal communication.
The TCP protocol can provide reliable communication connection for the application, make the byte stream sent by one computer send to other computers on the network without error, and the data communication system with high reliability is often transmitted by TCP protocol. Application protocol for TCP support: Telnet (remote login), FTP (File Transfer Protocol), SMTP (Simple Mail Transfer Protocol).

UDP protocol for non-connection

UDP for unreliable connections, packet loss, no check, fast, no handshake process
UDP is suitable for applications where only a small amount of data is transmitted at a time and the reliability requirements are not high. (The ping command is UDP) UDP supported application protocols: NFS (Network File system), SNMP (Simple Network Management System), DNS (primary Domain Name System), TFTP (Universal File Transfer Protocol), etc.

2.TCP handshake and four waves of three times

http://blog.csdn.net/whuslei/article/details/6667471/

The difference between post and get in 3.HTTP

Get is getting data from the server, and post is transferring data to the server. Get is to add the parameter data queue to the URL, and the value corresponds to the field one by one in the form. Post is the process of placing data in an HTML header and sending it together so that the user does not see it. For Get mode, the server end uses Request.QueryString to obtain the value of the variable, and for the Post method, the server end uses Request.Form to obtain the submitted data. The amount of data transferred by get is small and cannot be greater than 2KB. Post transfers have a large amount of data, which is generally default to unrestricted. In theory, however, the maximum number of IIS4 is 100KB in 80KB,IIS5. Get security is very low, post security is high. Get execution is highly efficient

The difference between 4.http and HTTPS

HTTPS protocol requires a CA to request a certificate, the general free certificate less, thus requiring a certain fee.
HTTP is a Hypertext Transfer protocol in which information is transmitted in clear text and HTTPS is a secure SSL encryption transport protocol.
HTTP and HTTPS use a completely different connection, the same port is not the same, the former is 80, the latter is 443.
HTTP connection is very simple, is stateless; HTTPS protocol is a network protocol built by Ssl+http protocol, which can encrypt transmission and authentication, and is more secure than HTTP protocol.