A,
TCP/IP (transfer control protocol/Internet protocol) is to point to to achieve information transmission between different network protocol suite, TCP/IP protocol not only refers to two TCP and IP agreement, but to a FTP, SMTP, TCP, UDP, IP agreement constitute the entire agreement of the cluster, such as only because TCP protocol in the TCP/IP protocol and IP agreement is the most representative, so called TCP/IP protocol,
Second, description
TCP/IP transport protocol, the transmission control/network protocol, also called a network communication protocol, it is the most basic in the use of the network communication protocol, TCP/IP transport protocol for each part of the Internet to communicate the standards and methods of regulation, and TCP/IP transport protocol is to ensure network data information in a timely manner, a complete transfer of two important protocol, TCP/IP transport protocol is strictly speaking is a system of four layers of structure, the application layer, transport layer, network layer and data link layer contain among them, the TCP/IP protocol is the basic of the Internet, one of the major application layer protocol Telnet, FTP, SMTP, etc., are used to receive data from the transport layer, or according to different application requirements and methods of data transmission to the transport layer; The major transport layer protocol is a UDP, TCP, is consumer USES computer information network platform and internal data channels, can realize the data transmission and data sharing; The major network layer protocol have ICMP, IP, IGMP, mainly responsible for the transfer of data packets over the Internet, etc.; The network access layer, also called the network interface layer and data link layer, the main agreement are ARP, RARP, main function is to provide the link management error detection, for different communication media information about the details for effective treatment, etc.,
Three,
TCP/IP protocol to a certain extent, the OSI reference architecture, there are seven layers of the OSI model, from bottom to top respectively are the physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer, but this is obviously a bit complicated, so in the TCP/IP protocol, they are simplified to four levels,
(1) the application layer, presentation layer, session layer three levels to provide service is not very big difference, so in the TCP/IP protocol, they are combined into the application layer a hierarchy,
(2) due to the transport layer and network layer in the status of the network protocol is very important, so they are in the TCP/IP protocol as a separate two levels,
(3) because the content of the data link layer and physical layer was similar, so they are merging in the TCP/IP protocol in a hierarchical network interface layer, only four layers architecture of TCP/IP protocol, compared with the OSI seven layers architecture is simple, also is such, TCP/IP protocol is more efficient in the actual application, lower cost,
Respectively introduces the four levels of the TCP/IP protocol, the
The application layer, application layer is the first layer of the TCP/IP protocol, is directly provide services for the application process,
(1) for different kinds of applications they can differ according to their own needs to use the application layer protocol, mail transfer applications use the SMTP protocol, the world wide web application using the HTTP protocol, remote login service applications use the TELNET protocol,
(2) the application layer can encrypt, decrypt, and formatting data,
(3) the application layer can create or remove links with other nodes, so that we can save the network resource fully,
Transport layer: as the second floor of the TCP/IP protocol, the transport layer in the TCP/IP protocol play a backbone role, and in the transport layer, TCP and UDP is also have the effect of the mainstay, the network layer, network layer in the TCP/IP protocol is located in the third layer, network layer in the TCP/IP protocol can termination as well as the IP address for the establishment of a network connection and search functions, such as: network interface layer in the TCP/IP protocol, the network interface layer is located in the fourth floor, because the network interface layer merging the physical layer and data link layer, so the network interface layer is not only the physical medium to transfer data, also can provide the network layer with a correct line,
Four, timeliness
Timing of the TCP/IP transport protocol refers to the use of the transmission of information in a certain situation, time frame, data information is valuable to the user, a more macro, timeliness of information includes data information after transfer interest the recipient and the influence on the society, but with the passage of time, the data information by using value will be more and more small, that is, the relevant data and information for the same things in different time periods you have big or small the value of the difference, the difference we called data information timeliness, TCP/IP transport protocol of data information transmission, to overcome the traditional way of information transmission lag, the delay, the problems of inefficient, TCP/IP transport protocol can often will effective information transfer to those who need in a timely manner, it can realize the maximization of the value of data and information, guarantee the timeliness of data information,
Five, the characteristics of the TCP/IP protocol
(1) the TCP/IP protocol is not dependent on any specific computer hardware or operating system, and provide an open protocol standard, even if they don't consider the Internet, TCP/IP protocol has gained widespread support, so the TCP/IP protocol as a combination of a variety of hardware and software of practical system, it can not only provide hardware agreement between also can be between software, can also be hardware and software interaction,
(2) the TCP/IP protocol does not depend on the specific Network transmission hardware, so the TCP/IP protocol can integrate all kinds of Network, users can use the Ethernet (Ethernet), Token Ring Network (Token Ring Network, dial-up line (Dial - up line), the x. 25 Network and all the Network hardware,
(3) a unified network address allocation, make the whole TCP/IP device has a unique address in the network, to facilitate accurate information about the precise transmission and interconnection;
(4) standardization of high-level protocol, can provide a wide range of reliable user services, such as HTTP, FTP protocol, such as
Six,
Socket is the encapsulation of TCP/IP protocol and application level (programmer), also, to say the TPC/IP protocol is a transport layer protocol, mainly solve how the data transmission in the network, and HTTP is the application layer protocol, mainly solve how to packing data, about the relationship between the TCP/IP and HTTP protocol, network I saw there was a relatively easy to understand introduction:
"We can only use in data transmission, TCP/IP protocol (transport layer), but in that case, if there is no application layer, can't identify the data content, if you want to make the transmission of data meaningful, it must be used in the application layer protocol, the application layer protocol has a lot of, such as HTTP, FTP, TELNET, etc., can also define the application layer protocol, WEB use HTTP protocol for application layer protocol, HTTP text to encapsulate information, then do using TCP/IP transport layer protocol will it sent to the Internet,"
Socket is what we say at ordinary times most, the socket is actually encapsulation of TCP/IP protocol, the socket itself is not a deal, but a call interface (API), through the socket, we can use TCP/IP protocol, in fact, the socket is no connection with TCP/IP, socket programming interface in the design, just hope can also adapt to other network protocols, so the emergence of the socket only allows programmers more easily using TCP/IP protocol stack, is an abstract of the TCP/IP protocol, we know that was formed by some of the most basic function of the interface, such as create, listen, connect, accept, send, read and write and so on, the network has a paragraph about the socket and TCP/IP protocol relationship is relatively easy to understand:
"TCP/IP is a protocol stack, just like running mechanism of the operating system, must be the specific implementation, but also provides foreign operation interface, this is like the operating system will provide standard programming interface, such as win32 programming interface, the TCP/IP to provide programmers will do network interface used in the development, this is the Socket programming interface,"
In fact, the TCP transport layer is based on the IP network layer protocol, and the application layer of the HTTP protocol is based on the TCP transport layer protocol, and the Socket itself is no agreement, as mentioned above, it just provides a for the TCP or UDP programming interface,
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