What does instant messaging mean?

Question 1: What is instant messaging? Instant messaging is such software, you tell me and I'll give you a reply. It is divided into individuals and enterprises. You must be familiar with penguins for individuals, but I recommend Yixin for enterprises.

Question 2: The difference between instant messaging and real-time messaging Instant messaging (im) and real-time messaging are both a set of network communication systems, and their essence is to forward information. The biggest difference is the time regulation of information transmission. The difference between the two can be seen from the following aspects:

First of all, the scene

Common instant messaging scenarios include text chat, voice message sending, file transmission, audio and video playback, etc. In layman's terms, it is to send text messages.

Real-time communication scenarios include voice, video teleconference, VoIP and so on. In layman's terms, it is to call.

Second, the product demand point

Instant messaging: The main requirement is the evaluation of reliability and delivery rate. If you send a text message, the message is lost and the other party doesn't receive it! You don't believe in text messages anymore.

Real-time communication: it mainly requires low delay and low connection rate.

Low latency: When you make a phone call, every time you say a word, it takes a few seconds for the other party to respond, so you can't talk on this phone.

Connection rate: I heard that I was connected when I was on the phone, but actually the other party's mobile phone didn't respond, and actually it wasn't connected. This is the same as the bad influence caused by not texting.

Third, the technical link.

Instant messaging technology links: message sending and confirmation, message logic processing at message access end and service end, message caching and storage and forwarding at service end, user state management at service end, heartbeat mechanism, message sender, message receiving and confirmation.

Real-time communication technology links: acquisition, preprocessing, coding, server access, forwarding, server access, decoding, playing and rendering.

The overlapping parts of these technical links are: information forwarding.

Fourth, the transmission protocol.

On the Internet, the most commonly used communication protocols are TCP and UDP.

TCP: Tran * * * issues a control protocol, and the transmission control protocol is a connection-based protocol, that is, a reliable connection must be established with the other party before data can be formally sent and received. It is characterized by uncontrollable delay.

UDP: user data protocol, user datagram protocol, which is a protocol corresponding to TCP. It is a non-connection-oriented protocol, which does not establish a connection with the other party, but sends data packets directly. It has the characteristics of packet loss, jitter and delay.

In order to ensure the reliability of the connection, the most commonly used instant messaging system is TCP protocol or TCP-like connection protocol. This kind of protocol is characterized by the pursuit of connection reliability, which leads to uncontrollable delay. The delay response of more than 2 seconds is normal, even tens of minutes, and the carrier-level real-time communication standard is 400ms, so the real-time communication based on the Internet needs to find another way and create a new transmission solution. This is related to the application scenario. Sending text messages, delaying sending for a few seconds, has little impact on users.

Real-time communication will use UDP as the basic transmission protocol. When designing low-latency real-time communication services, UDP has much better performance than TCP. This is because low latency is more important than reliability in real-time communication. On the phone, a few seconds' delay is unbearable.

TCP protocol encapsulates the message retransmission mechanism. In the case of packet loss, it is difficult to optimize this retransmission mechanism to achieve the effect of low delay by using TCP protocol. Especially in the mobile internet, when the packet loss exceeds 30%, the delay of TCP can reach tens of minutes, and when the packet loss exceeds 50%, it is even easy to disconnect the network. UDP can also transmit data on the same link with 30% packet loss, so TCP can't communicate in real time.

Based on UDP protocol, various algorithms are developed to compensate packet loss, on the one hand, to ensure and restore data continuity as much as possible. On the other hand, when some data packets cannot be recovered, the corresponding audio and video data packets will be discarded without affecting the subsequent real-time communication service.

Verb (abbreviation for verb) cost

The links involved in the cost are: server access, storage and forwarding. (Forget about labor costs)

Two types of links with different costs are:

From the server access mode, instant messaging uses TCP protocol to ensure reliability, and may establish multiple connections. Compared with connectionless UDP transmission mode, this is an expensive transmission mode. Real-time communication can be based on UDP protocol and establish a flexible and fast access mechanism with the server.

In terms of storage, real-time communication is forwarded in real time on the server side, and data will not be stored on the server side. However, instant messaging systems generally convert cache into stored data, including rich media data, which will occupy a lot of storage space and generate more storage costs.

From the cost point of view, the transmission of the same amount of information, instant communication based on TCP ... > >

Question 3: Definition of terms: What is instant messaging Instant messaging is the most popular communication mode on the Internet at present, and various instant messaging softwares emerge one after another. Service providers also provide more and more rich communication service functions. There is no doubt that the Internet has become a real information superhighway. From the point of view of practical engineering application, it is feasible to program and realize a network chat tool based on C/S architecture under the guidance of computer network principles and some common technologies in the current network.

At present, the enterprise-level instant messaging tools in China market mainly include homing pigeon, visual collaborative office platform for senior engineers, 263EM, Qunying CC20 10, Tongsoft United Go, RTX of Tencent, Lotus Sametime of IBM, GKE of Click Technology, imo of China Netcom Office, Fetion of China Mobile, E-link of Huaxia Yilian and Flag Raising. Compared with personal instant messaging tools, enterprise instant messaging tools emphasize security, practicality, stability and expansibility. [ 1]

Instant messaging (IM) is a real-time communication system, which allows two or more people to communicate with each other in real time by using the network. [2]

Chinese name

instant message

Chinese name

instant message

Translate a name

instant message

abbreviation

Instant message

classify

application software

Tomomi

real-time communication

Question 4: What is instant messaging? Instant messaging (IM) refers to a service that can instantly send and receive Internet messages. The instant messaging function in 1998 is becoming more and more abundant, and it gradually integrates many functions such as mail, blog, music, TV, games, search and so on. Instant messaging is no longer a simple chat tool, but has developed into a comprehensive information platform integrating communication, information, entertainment, search, e-commerce, office collaboration and enterprise customer service. With the development of mobile Internet, Internet instant messaging is also expanding to mobility. At present, Microsoft, AOL, Yahoo and other important instant messaging providers provide instant messaging services to access the Internet through mobile phones, and users can send and receive messages with other mobile phones or computers that have installed corresponding client software through mobile phones.

Baike.baidu/view/1Touch 88645.

Question 5: What does real-time chat mean? It means that two people are chatting with each other at the same time, usually through online chat tools.

Question 6: Introduction to Instant Messaging Instant messaging (IM) refers to the business that can send and receive Internet messages instantly. Since the advent of 1998, especially with the rapid development in recent years, the functions of instant messaging have become increasingly rich, and it has gradually integrated many functions such as mail, blog, music, TV, games and search. Instant messaging is no longer a simple chat tool, but has developed into a comprehensive information platform integrating communication, information, entertainment, search, e-commerce, office collaboration and enterprise customer service.

Question 7: What is instant messaging software? VOIP (Internet Phone) can directly dial the other party's fixed phone and mobile phone through the Internet, and can make domestic and international calls anytime and anywhere, with clear and stable call quality, and the tariff is only 10%-20% of that of traditional phones, which can help users greatly save phone bills. VOIP (Internet Phone) is loved by more and more users because of its low cost and convenience. Can be divided into software mobile phones and hardware mobile phones.

Softphone: Softphone is to download software on a computer/mobile phone/tablet, then buy a network calling card, and then make a call with the other party (fixed line or mobile phone) through headphones or other terminals;

Hardware telephone: Hardware telephone is more suitable for companies, telephone bars and so on. First, you need a voice gateway. One side of the gateway is connected to the router, and the other side is connected to the ordinary telephone, and then the ordinary telephone can be freely called out through the network. The answer comes from the bee cloud intelligent website.

Question 8: What are the service functions of search engines and instant messaging? Search engine is a retrieval tool, which is used to search keywords and present relevant results. Users can click to view, the information already exists.

Instant messaging is a one-to-one communication tool, online and real-time.

Question 9: What is instant messaging software? Instant messaging (IM) is a terminal service that allows two or more people to communicate with each other instantly in the form of text messages, files, voice and video.

Instant messaging can be divided into enterprise instant messaging and website instant messaging according to the purpose of use, and can be divided into mobile phone instant messaging and PC instant messaging according to the loading object.

Mobile instant messaging stands for short message.

PC instant messaging such as QQ, MSN, Baidu hi, etc.