Introduction and comparison of common network communication protocols

1. VMess
VMess (Virtual Machine Mess) is an encrypted communication protocol based on the VMess protocol, which was developed by V2Ray (an open source network proxy tool). The VMess protocol is designed to provide secure and efficient communication, mainly used for communication between proxy servers and clients.

The VMess protocol has the following features:
Encryption and security: VMess uses powerful encryption algorithms such as AES-128-CFB, AES-128-GCM, Chacha20-Poly1305, etc. to ensure the confidentiality and integrity of data. It also supports the TLS (Transport Layer Security) protocol to provide end-to-end encrypted communication.

Multiplexing: VMess protocol supports multiplexing, that is, multiple data streams can be transmitted on the same TCP connection. This means that multiple requests can send and receive data through one connection at the same time, which improves the efficiency of communication.

Dynamic ports: The VMess protocol uses dynamic ports for communication, so that each connection uses a different port number. This increases the stealthiness of communication and makes network traffic more difficult to identify and interfere with.

Load balancing: The VMess protocol supports load balancing, which can distribute incoming requests to multiple servers to achieve high availability and performance optimization.

Client and Server: VMess protocol involves two main roles, client and server. The client connects to the proxy server, sends requests and receives responses. The server receives the request and forwards the data stream to the target server or other proxy servers.

Supported platforms: The VMess protocol is available on multiple platforms, including Windows, Linux, macOS, and Android, etc. This makes it widely applicable and can be used to build various network proxy and tunnel applications.

Summarize
The VMess protocol is a powerful, secure and reliable encrypted communication protocol. It provides an efficient and secure communication method for network proxies and tunnels through encryption, multiplexing and load balancing.

2. vless
VLess (Virtual Less) is a lightweight encrypted communication protocol that is simplified and optimized based on the VMess protocol. It was developed by V2Ray and aims to provide a simpler and more efficient communication method.

Compared with the VMess protocol, the VLess protocol has the following characteristics:
Simplified configuration: The VLess protocol simplifies the configuration process and reduces the complexity of the configuration file. Compared with the VMess protocol, which requires a series of parameters and options to be set, the VLess protocol only requires fewer parameters to be set, making the configuration simpler and easier to use.

Fewer encryption methods: The VLess protocol removes some encryption algorithms from the VMess protocol and only retains one encryption method, AEAD (Authenticated Encryption with Associated Data). The AEAD encryption algorithm combines the functions of encryption and authentication to ensure the confidentiality and integrity of data.

Simplified transmission format: The VLess protocol uses a simplified transmission format, which reduces the size of data packets and transmission delays. This makes communication more efficient and reduces network transmission overhead.

Dynamic port: The VLess protocol, like the VMess protocol, also uses dynamic ports for communication, ensuring that each connection uses a different port number, increasing the concealment and security of communication.

Supported platforms: The VLess protocol supports multiple platforms, including Windows, Linux, macOS, and Android, and has the same wide applicability as the VMess protocol.

Summarize
The VLess protocol is an encrypted communication protocol that is simplified and optimized based on the VMess protocol. It provides a more lightweight and efficient communication method by simplifying configuration, streamlining transmission format, and retaining key encryption functions. The VLess protocol still provides secure encrypted communication and is suitable for building various network proxy and tunnel applications.

3. Trojan
The Trojan protocol is an encrypted proxy protocol based on the HTTP/HTTPS protocol, designed to disguise itself as common web traffic, bypass network censorship and firewall restrictions to achieve secure and private communications. The Trojan protocol was originally designed to provide concealment and privacy protection, allowing users to freely access the Internet in a restricted network environment.

The Trojan protocol has the following characteristics:
Disguised as common traffic: Trojan protocols use HTTP/HTTPS protocols as transmission carriers, making their communications look like normal web traffic. This disguise makes it difficult to be detected by network censorship and firewalls, thereby achieving free access to the network.

Encrypted communication: The Trojan protocol ensures data security during transmission by encrypting communication data. It supports commonly used encryption algorithms such as AES, RSA, etc. to protect the confidentiality and integrity of data.

Client and Server: The Trojan protocol involves two main roles, the Trojan client and the Trojan server. The client is used to establish a connection with the server and send the user's request to the server through an encrypted channel. The server receives the request and forwards the data to the real target server or other proxy server.

Custom ports: Trojan protocols use custom ports for communication, often using non-standard port numbers. This increases the stealthiness of the protocol, making network traffic more difficult to identify and interfere with.

Supported platforms: The Trojan protocol is available on multiple platforms, including Windows, Linux, macOS, and Android. This makes it widely applicable and can be used to build various network proxy and tunnel applications.

Summarize
The Trojan protocol is an encrypted proxy protocol based on HTTP/HTTPS. It enables secure and private communication in a restricted network environment by disguising itself as common web traffic. It provides features such as encrypted communication, custom ports, and cross-platform support, and is suitable for scenarios that need to bypass network censorship and firewall restrictions. However, the use of the Trojan protocol requires compliance with relevant laws and regulations to ensure legal and compliant use.

4. Shadowsocks
The Shadowsocks protocol is an encrypted communication protocol based on the Socks5 proxy protocol, which aims to provide secure and private network proxy services. The Shadowsocks protocol is designed to bypass network censorship and firewall restrictions, allowing users to access the Internet freely.

The Shadowsocks protocol has the following features:
Proxy mode: The Shadowsocks protocol uses proxy mode. The client sends the network request to the Shadowsocks server, which encrypts and forwards the request and finally transmits the data to the target server. This proxy mode allows the user's real IP address and data content to be hidden.

Multiple encryption algorithms: Shadowsocks protocol supports multiple encryption algorithms, including AES, Blowfish, RC4, etc., to protect the confidentiality and integrity of communication data. Users can choose the appropriate encryption algorithm according to their needs.

Custom ports: The Shadowsocks protocol uses custom ports for communication, usually non-standard ports. This increases the stealthiness of the protocol and makes network traffic more difficult to identify and interfere with.

Client and server: The Shadowsocks protocol involves two main roles, the Shadowsocks client and the Shadowsocks server. The client connects to the server and sends the user's request to the server, which encrypts the request and forwards the data to the target server or other proxy server.

Cross-platform support: The Shadowsocks protocol is available on multiple platforms, including Windows, Linux, macOS, and Android, etc. This makes it widely applicable and can be used to build various network proxy and tunnel applications.

6. Socks
Socks (Socket Secure) is a universal network proxy protocol that defines a set of standard proxy service interfaces. The Socks protocol is divided into multiple versions, of which Socks5 is the latest version. The Socks protocol can provide proxy functions between the application layer and the transport layer in the TCP/IP protocol stack to achieve network data forwarding and proxy access.

The characteristics of the Socks protocol include:
Proxy function: The Socks protocol allows the client to establish a connection with the target server through the Socks proxy server and forward data through the proxy. The client sends a request to the proxy server, which is responsible for forwarding the request to the target server and returning the target server's response to the client.

Socks5 protocol features: Socks5 is the latest version of the Socks protocol, supporting multiple authentication methods and multiple transport layer protocols. It provides more powerful functions and better performance, including support for UDP forwarding, authentication options, multiple proxy methods, etc.

Application transparency: Socks protocol is transparent to applications.

Transparently, applications can access network resources through the Socks proxy server without modification. This makes the Socks protocol very flexible and suitable for various network application scenarios.

Widely supported: The Socks protocol is widely supported, and many operating systems and network applications have built-in support for Socks proxies. This makes the Socks protocol easy to configure and use.
Summarize
Shadowsocks and Socks are both protocols used to provide network proxy services. Shadowsocks focuses on encryption and bypassing network censorship, while Socks provides general proxy functionality. Both have wide applicability and are used to build various network proxy and tunnel applications.

7. Dokodemo-door
Dokodemo-door (i.e. "Any Door") is a general traffic forwarding protocol developed by V2Ray, which is designed to forward traffic from one inlet to a specified outlet. It can be used to implement highly customized traffic forwarding and processing, allowing users to customize rules and operations.

The characteristics of the Dokodemo-door protocol are as follows:
Anydoor: Dokodemo-door allows users to define the inlet and outlet of traffic, and forward traffic from the specified inlet to the specified outlet. The inlet and outlet can be local or remote addresses, ports, protocols, etc.

Traffic forwarding: Dokodemo-door forwards traffic through a proxy server. The client sends traffic to the designated entrance of the proxy server, and the proxy server forwards the traffic to the designated exit according to the rules defined by the user.

Flexible rule configuration: Dokodemo-door protocol supports users to define rules and operations according to their own needs. Users can set rules based on conditions such as target address, port, protocol, etc. to achieve customized forwarding and processing of traffic.

Traffic processing: Dokodemo-door can not only realize simple traffic forwarding, but also perform a series of traffic processing operations, such as traffic encryption, decryption, modification of message headers, load balancing, etc. This allows users to customize traffic according to specific needs.

Supported platforms: The Dokodemo-door protocol can be used on multiple platforms, including Windows, Linux, macOS, and Android. It works with V2Ray to provide cross-platform traffic forwarding and processing capabilities.

Summarize
Dokodemo-door protocol is a general traffic forwarding protocol that allows users to forward traffic from a specified inlet to a specified outlet and supports customized rules and traffic processing operations. It provides flexibility and scalability and can be used to build various network proxy and tunnel applications to meet the customized needs of different users.

8. http and https
HTTP (Hypertext Transfer Protocol) is an application layer protocol used to transfer hypertext data between web browsers and web servers. The HTTP protocol is based on the client-server model. The client sends an HTTP request to the server, and the server responds to the request and returns the corresponding data.

The characteristics of HTTP protocol are as follows:
Simple: The design of HTTP protocol is simple and clear, easy to understand and implement. It uses text-formatted request and response messages, including HTTP methods, URLs, header fields, and message bodies.

Stateless: The HTTP protocol is stateless, that is, the server does not retain the state information of the client request. Each request is independent, and the server only responds according to the request and does not remember the previous request information.

Based on TCP/IP: The HTTP protocol is based on the TCP/IP protocol stack and uses TCP as the transport layer protocol. Both HTTP requests and responses are transmitted over TCP connections.

Plain text transmission: HTTP protocol data transmission is in plain text, and the data is not encrypted. This means that the communication content of HTTP can be eavesdropped and tampered with, which lacks security.

HTTPS (Hypertext Transfer Protocol Secure) is an extended protocol that adds security to the HTTP protocol. It uses the SSL (Secure Sockets Layer) or TLS (Transport Layer Security) protocol to encrypt data and authenticate identities to ensure communication security.

The characteristics of the HTTPS protocol are as follows:
Encrypted communication: HTTPS uses the SSL/TLS protocol to encrypt HTTP communications to ensure the confidentiality and integrity of data during transmission. By using public key encryption and private key decryption technology, it ensures that data can only be decrypted and read by legitimate communication parties.

Authentication: The HTTPS protocol uses digital certificates to authenticate the server, ensuring that the client is connected to a legitimate server. Digital certificates are issued by a trusted third-party certificate authority (CA) and are used to verify the server's identity.

Port: HTTPS uses port 443 by default for communication, which is different from HTTP's default port 80. This helps distinguish between normal HTTP traffic and encrypted HTTPS traffic.

Compatibility: The HTTPS protocol is compatible with the HTTP protocol, so most modern web browsers and web servers support HTTPS. By adding "https://" to the URL, you can use the HTTPS protocol for secure communication.

Summarize
The HTTP protocol is a simple protocol for transmitting hypertext data between a web browser and a web server, while the HTTPS protocol is a security extension protocol that adds encryption and identity authentication to the HTTP protocol. HTTPS encrypts data using the SSL/TLS protocol, providing a more secure communication method, which is suitable for scenarios that protect sensitive information and privacy, such as online payment, login, etc.