What types of networks can be classified according to communication methods?

Networks can be divided into two categories according to communication methods: 1. Broadcast transmission network, which uses a common transmission medium to connect various sites so that online sites share a channel. Any one site outputs, and other sites All are acceptable. Suitable for networks with small scope or low confidentiality requirements. 2. Point-to-point transmission network is a point-to-point transmission of data in computers or communication equipment. It is an Internet system that has no central server and relies on user groups (peers) to exchange information. Its function is to reduce the cost of previous network transmission. nodes to reduce the risk of data loss.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

Networks are classified according to communication methods and can be divided into: broadcast transmission network and point-to-point transmission network.

Broadcast transmission network

Use a common transmission medium to connect various sites so that online sites share a channel. The output of any one site can be received by other sites. Suitable for networks with small scope or low confidentiality requirements.

There is only a single communication channel in the network, shared by all hosts in the network. That is, multiple computers are connected to different branch points on a communication line, and message packets sent by any node are accepted by all other nodes. There is an address field in the sent packet that specifies the intended recipient and source address of the packet.

Broadcast networks can be further divided into static and dynamic ones. The criterion for division is the allocation method of channels. A typical static allocation scheme is to divide time into discrete intervals and use a polling algorithm so that each machine can broadcast data only when its own time slot arrives. If a machine does not need to send data in the time slot to which it is assigned, then this static allocation scheme wastes the channel transmission capacity, so most systems use dynamic allocation of channels.

Point-to-point transmission network

A point-to-point transmission network is a point-to-point transmission of data in computers or communication devices. Star networks and ring networks use this transmission method.

Peer-to-peer (P2P), also known as peer-to-peer network, is an Internet system that has no central server and relies on user groups (peers) to exchange information. Its function is to reduce the nodes in network transmission to reduce the risk of data loss. Different from a central network system with a central server, each client in the peer-to-peer network is both a node and a server. No node cannot directly find other nodes and must rely on its user group for information exchange.

P2P nodes can be spread throughout the Internet, which also brings monitoring problems to any person, organization, or government, including developers. P2P has been widely used in areas with high network privacy requirements and file sharing. Network systems using pure P2P technology include Bitcoin, Gnutella, or Freenet, etc. In addition, P2P technology is also used in data communications for real-time media services such as VoIP. Some networks (such as Napster, OpenNAP) include some search functions and also use a client-server structure, while using a P2P structure to implement other functions. This network design model differs from the client-server model, in which communications typically go to and from a central server.

Characteristics of P2P network

An important goal of P2P network is to enable all clients to provide resources, including bandwidth, storage space and computing power. Therefore, when nodes join and requests to the system increase, the capacity of the entire system also increases. This cannot be achieved with a Client-Server structure with a fixed set of servers, because in such a structure, the increase in clients means slower data transmission for all users.

The distributed nature of the P2P network also increases the robustness against failures by replicating data on multiple nodes, and in a pure P2P network, nodes do not need to rely on a central index server to discover data. In the latter case, there is no single point of collapse for the system.

When describing the Napster network in terms of P2P, the peer-to-peer protocol is considered important, but in practice, what the Napster network achieves is that peer nodes (like the branches of the network) unite to a central index. accomplish. This allows it to quickly and efficiently locate available content. Peer-to-peer protocols are just a general way to do this.

Advantages

• Have better parallel processing capabilities.

• Use memory to manage exchange data and greatly improve performance.

• No need to invest a lot of money in server software and hardware equipment.

• Suitable for small-scale networks and easy to maintain.

##Disadvantages

• The setup is more complicated. In addition to the development server, a dedicated client is also required.

• Used in large-scale networks, resource sharing is chaotic, management is difficult, and security is low.

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