scada protocols

, there were two versions of "0.9 and 1.0", with HTTP 0.9 "not" widely used, and HTTP 1.0 being widely used.In addition, it is said that the IETF will release the HTTP 2.0 standard next year. I'll wait and see.2. The relationship between HTTP and TCPSimply put, the TCP protocol is the cornerstone of the HTTP protocol--http protocol needs to rely on the TCP protocol to transfer data.In the network layering model, TCP is called the Transport Layer protocol, and HTTP is called the application-layer

versions of "0.9 and 1.0", with HTTP 0.9 "not" widely used, and HTTP 1.0 being widely used.In addition, it is said that the IETF will release the HTTP 2.0 standard next year. I'll wait and see. The relationship between HTTP and TCP Simply put, the TCP protocol is the cornerstone of the HTTP protocol--http protocol needs to rely on the TCP protocol to transfer data.In the network layering model, TCP is called the Transport Layer protocol, and HTTP is called the application-layer pr

(All of the following is the hand of pure hand, there are flaws in the place, please also contain a lot of information to send piglets to exchange!) ）(All content and annotations in this article are displayed in the recursive architecture, because the format display does not understand the point of understanding!) ）(In this paper, the command keyword is mostly used shorthand, if there is an unknown, it is best to type the command when you use TAB completion!) ）cisco-sw-three-layer switching betw

"not" widely used, and HTTP 1.0 being widely used.In addition, it is said that the IETF will release the HTTP 2.0 standard next year. I'll wait and see.2. The relationship between HTTP and TCPSimply put, the TCP protocol is the cornerstone of the HTTP protocol--http protocol needs to rely on the TCP protocol to transfer data.In the network layering model, TCP is called the Transport Layer protocol, and HTTP is called the application-layer protocol.There are many common application-layer

Import UIKitClass viewcontroller2:uiviewcontroller,uitableviewdelegate,uitableviewdatasource{Override Func Viewdidload () {Super.viewdidload ()Self.view.backgroundcolor=uicolor.orangecolor ()var Mytableview = UITableView (frame:cgrectmake (0, 0, UIScreen. Mainscreen (). Bounds.size.width, Uiscreen.mainscreen (). bounds.size.height), Style:UITableViewStyle.Plain)Self.view.addSubview (Mytableview)Mytableview.delegate = SelfMytableview.datasource = SelfMytableview.backgroundcolor = Uicolor.whitecol

Steps......... /**① Child View definition protocol: @protocol *② define proxy @property (weak,nonatomic) ID in the Child view interface file Protocols and proxies for IOS

"MyProtocal.h" #import "MulProtocal.h" @implementation person Main.m#import Four agentsTicketdelegate.h@protocol ticketdelegate Agent.h@protocol ticketdelegate, @interface agent:nsobject Person.h@class agent, @class ticketdelegate, @interface person:nsobject-(void) buyticket;//Proxy Properties @property (nonatomic , retain) ID Person.m#import "Person.h" #import "Agent.h" @implementation person-(void) buyticket{if (_delegate [_delegate Leftticketsnumber] > 0) {NSLog (@ "buy ticket");}} @endMain

all extend javax. servlet. GenericServlet. There are few classes, interfaces, and methods in the SIP Servlet specification, which allows people to easily and quickly master their basic knowledge. The operation of SIP is to "ping" other devices. In essence, it is to execute an INVITE message request to establish a session between devices. This is usually called Call Control-creating and cutting off media streams, such as phones. A session can be of almost any type and is not so much a SIP protoc

The driving force of technological development is the constant demand of people. With the increasing use of the Internet, the current network protocol version is no longer able to meet the needs of the times. Inevitably, we will launch a new generation of IPv6 network protocols that are more complete and have diverse functions. The inevitable elimination of IPv4 indicates that the development of the network will usher in its first innovation. IPv6 is

A Router is a network device used to connect multiple networks or CIDR blocks. These networks can be networks that use different protocols and architectures (such as the Internet and LAN), or networks of different network segments (such as networks of different departments in a large Internet ), when data is transmitted from one department network to another department network, you can use a router. Nowadays, more and more local networks are using vro

NAT, DHCP, and DNS protocols. First, NAT. Network Address Translation (NAT, Network Address Translation) is a WAN Access Technology) it is widely used in various Internet access methods and networks. The reason is simple. NAT not only perfectly solves the problem of insufficient lP addresses, but also effectively avoids attacks from outside the network and hides and protects the computer www.2cto.com Dynamic Host Configuration Protocol inside the netw

, the attacker can use the Discovery Protocol to learn information about the detours connected to the device, this provides important information for the next attack. If you want to disable CDP at the global level, you can use the no cdp run Command in global configuration mode. 5. Sometimes the Protocol may also go wrong. Pay attention to the status of cdp in the ISO7 layer architecture. The Discovery protocol is one of the Layer 2 protocols specifie

Metric ). In RIP, the number of hops from a router to a directly connected network is 0, and the number of hops from one router to another is 1. To limit the convergence time, RIP requires the metric value to be 0 ~ An integer between 15 and 16. The number of hops greater than or equal to 16 is defined as Infinity, that is, the destination network or host is inaccessible. AD = 120) To improve performance and prevent the generation of routing loops, RIP supports horizontal Split Horizon) and rou

provides communication sessions between computers. The selection of transmission protocols depends on the data transmission mode.Two transmission protocols:Transmission Control Protocol TCP: provides reliable communication connections for applications. It is suitable for transmitting a large amount of data at a time. It is applicable to applications that require responses.User Datagram Protocol (UDP): provides connectionless communication and does no

follow the Login Format, registration format, message sending format, and so on in the design. Therefore, for complex network programs, more command formats are added, and the workload increases in actual design. In network programming, for the same network program, two network protocol formats are generally involved: the client sends data format and the server feedback data format. In actual design, one-to-one correspondence is required. This is the basic knowledge of network

There is no fixed standard for understanding the Wireless Router Protocol. Generally, the standard is IEEE 802.11g. Other content of the wireless router is described in detail later. In our contact, these standards have little impact on us. Wireless Router Protocol Standard Currently, wireless routers support the IEEE 802.11g Wireless Router Protocol and are backward compatible with 802.11b. First, we need to understand the meaning of this standard. IEEE, an international wireless standards orga

The network and Protocol transport layers in the TCP/IP model define two end-to-end protocols: TCP and UDP. TCP (Transmission Control Protocol) Transmission Control Protocol, which divides the input byte stream into packet segments and sends them to the Internet layer. TCP also needs to process traffic control to prevent the receiver from being unable to process too many packets sent to the low-speed receiver. Www.2cto.com UDP (User datainprotocol) Us

wireless network channels, which is a bit the same as normal mailing. If we do not encrypt the data files, we can directly transfer them in the wireless network, the wireless workstation around the local wireless network may intercept data files that do not adopt encryption protection measures, and the data files sent locally will leak the privacy information; if we do not want these data files to leak external privacy information, we should encrypt them or take other security measures before t

Graphic TCP-IP protocols (1) In this paper, two diagrams are used to sort out the knowledge of TCP-IP protocol. The TCP communication process consists of three steps: establishing a TCP connection channel, transmitting data, and disconnecting a TCP connection channel. 1 shows the TCP communication process. Figure 1 TCP three-way handshake Figure 1 consists of three parts: establishing a connection, transmitting data, and disconnecting. 1) it is ea

Chinese information on HTTPS is relatively small, this article focuses on the HTTPS protocol involved in the important knowledge points and usually not easy to understand the blind area, hoping to understand the HTTPS protocol is helpful. Baidu HTTPS performance optimization involves a lot of content, from the front page, back-end architecture, protocol features, encryption algorithms, traffic scheduling, architecture and operation, security and other aspects have done a lot of work. The articl