Turn: https://www.cnblogs.com/candle806/archive/2011/11/09/2242273.html#4339824
If you want to continue down this road test, then following those things that we have to master, at least you do not want to stop at the simple black box ~ ~ In fact, always wanted to go to Linux application under test, so You can learn a lot of things will be, and will be very useful. Prior to listen to a small cloth teacher, if you want to go on long-term development in IT technology, then you boldly embrace Linux, because here you can learn something far superior to what you learned in the Windows platform stuff, most of which the classic passage is this: if you have been following Microsoft's technology, it will eventually dragged dead, because Microsoft's technology has been changing, and you need to continue to learn from him. And Linux is not the same, it is more for you to understand the underlying technology, so you go from the principle of understanding core technologies, always maintaining the status quo attitude to face the future of technological innovation.
I think as a tester, if you do not come into contact network, data communications technology, so we long way to go, at least I think that software testing is not only stay in the upper application, and the highest level of testing should be the test underlying core technology to test results ~ ~ ~ so we should have a grasp of technical analysis through architecture, protocol packet analysis and so on: TCP / IP, Socket, multithreading, these are a must.
1, take a look at the architecture of TCP / IP, as shown below:
TCP / IP protocol is actually in physical online a complete set of network protocols. Wherein the TCP transport layer is to provide services, and the IP network layer is to provide services. The following is a description of the protocol of the individual layers:
Stored on the Internet Protocol (Internet Protocol) is responsible for routing data between a host and network data: IP. Also provides packet transmission services for ICMP, TCP, UDP. This process usually involves the user does not need one.
ARP: ARP (Address Resolution Protocol)
This agreement will map a network address to the hardware address.
RARP: Reverse Address Resolution Protocol (Reverse Address Resolution Protocol)
This agreement will be mapped to a hardware address of the network address
ICMP: Internetwork Packet Control Protocol (Internet Control Message Protocol)
This error control protocol processing and transmitting gateway and a host.
TCP: Transmission Control Protocol (Transmission Control Protocol)
This is a process to provide to the user a reliable full duplex byte stream connection-oriented protocol. It is to provide virtual circuit services to user processes and to establish checks for the reliable transmission of data. (Note: Most Internet users that use TCP)
UDP: User Datagram Protocol (User Datagram Protocol)
This is provided to the user process connectionless protocol, for transmitting data without performing validity checks.
FTP: File Transfer Protocol (File Transfer Protocol)
It allows the user to operate the way the document (document add, delete, change, search, transfer, etc.) communicate with each other with another host.
SMTP: Simple Mail Transfer Protocol (Simple Mail Transfer Protocol)
SMTP mail transfer protocol between systems.
TELNET: Terminal Protocol (Telnet Terminal Procotol)
The virtual terminal mode allows the user to access a remote host
HTTP: Hypertext Transfer Protocol (Hypertext Transfer Procotol)
TFTP: Trivial File Transfer Protocol (Trivial File Transfer Protocol)
2, the core of the TCP / IP protocol is a transport layer protocol (TCP, UDP), a network layer protocol (IP) and the physical interface layer, the three layers are usually implemented in an operating system kernel. Usually the user's service needs to be achieved through the application, so the bottom layer and the application layer is to be achieved through a socket, which is what we usually refer to the Socket to establish the connection. Specifically as shown below:
TCP / IP protocol and application core relationship as shown above, so this comparison chart to understand our application-layer development, it is more intuitive, especially for some applications performance testing, what protocol-based communications, the analysis will handy.