Day 02-Computer Network Communication Protocol
1. four factors that influence network communication
1.1. Rules or Agreements
Rules or protocols govern how messages are sent, directed, received, and interpreted.
As long as human communication can take place in an instant, then there are thousands of communication processes that can be completed within 1 s. In order to complete such work, network processes must be strictly controlled, from cable design to digital signals being sent. These rules are also called protocols. These protocols work together and are known as the TCP/P protocol suite. The TCP/IP protocol suite works alongside other protocols, such as the Extensible Message Presence Protocol (XMPP), an instant messaging protocol that provides communication rules involving different devices.
Here are some common services and the protocols that support them:
A message or message unit is transmitted from one device to another.
It doesn’t matter if the message is text, voice, or video, because all formats are converted into bits, binary-coded digital signals, and transmitted over wireless, wired copper, or fiber. The digital signal changes as the transmission medium changes, but the content of the original message remains intact.
A medium is a means of connecting these devices; that is, a message can be transmitted from one device to another.
Wired connection: The medium can be copper cables that carry electrical signals or optical fibers that carry optical signals.
The medium is Earth’s atmosphere to get into space, and the signal is microwaves. During a typical Internet transmission, information may travel through a variety of media.
Devices on the network exchange information with each other.
Several devices, such as switches and routers, are responsible for the proper transmission of messages from the source or sending device to the destination device. There may be more switches, cables, or wireless routers in the target network that will send the instant message to the recipient.
Attachment: Some network equipment symbols
Two users on different network terminal devices can communicate only if many complex procedures are completed. These processes include messages, some media, different devices and protocols.
2. Protocol for network communication
In a computer network, the two communicating parties are computers. In order to enable normal communication between computers, strict communication rules, conventions, and standards must be formulated to accurately transmit the format and timing of data. These rules, conventions, and standards are network communication protocols.
Most networks use a layered architecture in which each layer is built on its lower layer, provides certain services to its upper layer, and hides the details of how these services are implemented from the upper layer.
The rule by which layer n on one device communicates with layer n on another device is called the layer n protocol. There are many protocols in each layer of the network. The protocols of the receiver and sender must be consistent; otherwise, one party will not be able to identify the information sent by the other party.
2.1 Network communication consists of three parts.
2.1.1 Semantics (What to do?)
Explain the meaning of each part of the control information. It specifies what kind of control information needs to be issued, and what kind of action to complete and what kind of response to make.
2.1.2 Syntax (how to do it?)
The structure and format of user data and control information and the order in which the data appears
2.1.3 Timing (when to do it?)
a detailed description of the sequence of events.
The knowledge points of the article are matched with the official knowledge files, which can further learn related knowledge.
Read Also :