Definition of network protocols

Network protocols are the basis for the development of the Internet. If we want to control the network well, we must have a clear understanding of network protocols. Here we will explain some elements of the network protocol. A network protocol includes at least three elements:

The syntax is used to specify the information format. The format, encoding, and electrical equality of data and control information.

Semantics is used to describe how the communication parties should do, and control information for coordination and error handling.

Time Series timing) describes the sequence of events in detail; speed new balance 576-degree matching and sorting. How network protocols work

How do computers on the network exchange information? Just as we speak in a language, there is also a language between various computers on the network. This is the network protocol. Different computers must use the same network protocol for communication.

The network protocol is a set of communication rules between network servers, computers, switches, routers, firewalls, and other devices on the network, it specifies the format required for communication and the meaning of these formats. most networks adopt a layered architecture. Each layer is built on its lower layer to provide certain services to its upper layer, the details of how to implement this service are shielded from the new balance 576 shoes on the previous layer. the rules for communication between layer n on one device and layer n on the other device are layer n protocol. there are many protocols in each layer of the network. The protocol between the receiver and the sender must be consistent. Otherwise, one party cannot identify the information sent by the other party. the network protocol enables various devices on the network to exchange information with each other. common protocols include TCP/IP, IPX/SPX, and NetBEUI.

How do computers on the network exchange information? Just as we speak in a language, there is also a language between various computers on the network. This is the network protocol, different computers must use the same network protocol for communication. of course, there are also a number of Network Association new balance running shoe discussions. The specific protocol to choose depends on the situation. computers on the Internet use the TCP/IP protocol.

The main reason for the success of ARPANET is that it uses the TCP/IP standard network Protocol, TCP/IPTransmission Control Protocol/Internet Protocol) ---- Transmission Control Protocol/Internet Protocol is a standard network protocol used by the Internet. it is a network architecture and protocol specification launched by ARPA from 1977 to 1979. with the development of Internet, TCP/IP has been further researched, developed, and applied to become the "general language" on Interne kids new balance shoes t ". hierarchical Structure of network protocols

Due to the complexity of the connection between network nodes, complex components are usually divided into some simple components during protocol preparation and then combined. the most common compound technology is the hierarchical method. The hierarchical structure of network protocols is as follows:

1) Each layer in the structure requires clear service and interface standards.

2) Use your applications as the highest level

3) In addition to the highest level, each layer in the middle provides services to the next layer, and users at the same time.

4) The physical communication line is used as the lowest layer. It uses the parameters transmitted from the new balance kids shoe at the highest level as the basis for providing services.

In order to allow computers produced by different computer manufacturers to communicate with each other and establish computer networks in a larger scope, ISO proposed the "Open System Interconnection Reference Model" in 1978 ", that is, the famous OSI/RM Model Open System Interconnection/Reference Model ). it divides the communication protocol of the computer Network architecture into seven layers, namely, the physical Layer Physics Layer), the Data Link Layer of the Data Link Layer), and the Network Layer new balance 576 walking Network Layer) transport Layer), Session Layer), Presentation Layer), Application Layer ).

The data transmission service is completed at the lower layer, and the above layer is oriented to users. there are at least two standards for each layer: service definition and protocol specification. the former provides an accurate definition of the services provided by the layer, and the latter describes the actions of the Protocol and various related procedures in detail to ensure the provision of services.

Application Layer Session Layer transport layer network layer data link layer physical layer LAN common three network new balance 576 mens network protocols

[2] TCP/IP is undoubtedly one of the most important of the three protocols. As a basic Internet protocol, it is impossible to access the Internet without it, any Internet-related operations are inseparable from the TCP/IP protocol. however, the TCP/IP protocol is also the most troublesome configuration among the three protocols. It is better to use a single machine to access the Internet. However, if you access the Internet through a LAN, you must set the IP address, gateway, and subnet mask in detail, DNS server and other parameters.

Although TCP/IP is currently the most popular network protocol, the communication efficiency of TCP/IP protocol in LAN is not high, new balance m576 browsing failures often occur. the NetBEUI protocol is installed to solve this problem.

NetBEUI is the NetBios Enhanced User Interface, or the NetBios enhancement User Interface. it is an enhanced version of the NetBIOS protocol and has been used by many operating systems, such as Windows for Workgroup, Windows 9x series, and Windows NT. the NETBEUI protocol is useful in many cases. It is the default protocol of the operating system before Windows 98. the NetBEUI protocol is a short and concise broadcast protocol with high communication efficiency. It does not need to be set after installation. It is especially suitable for new balance 580 shoes to transmit data in "Network neighbors. in addition to the TCP/IP protocol, it is recommended that the NetBEUI protocol be installed on computers in Small Lan. in addition, if you want to add a Windows 98 machine with only TCP/IP protocol to the WINNT domain, you must also install NetBEUI agreement.

The IPX/SPX protocol was originally developed by Novell for the NetWare network, but it is also very common now-most online games support IPX/SPX protocols, such as Starcraft, counter-terrorism elites, etc. although these games can also be online through the TCP/IP protocol, it is clear that it is easier to use the IPX/SP new balance 580 X protocol because no configuration is required. in addition, the IPX/SPX protocol does not seem to be very useful in the local area network. If you are sure that you are not playing games on a local area network, this protocol is dispensable. network Protocol by Purpose

Network Layer Protocol: includes: IP protocol, ICMP protocol, ARP protocol, RARP protocol.

Transport Layer Protocol: TCP protocol and UDP protocol.

Application Layer Protocol: FTP, Telnet, SMTP, HTTP, RIP, NFS, DNS.