The Bishe project is a small car. I have always wanted to link the data of the Raspberry Pi to Alibaba Cloud. I feel that I need to learn other knowledge in order to realize this. Then open a hole first, it will be updated slowly, and record what you learned during the period:
socket programming
I have come into contact with some knowledge of socket programming. During the period, I found a related blog for reference: socket PHP: detailed and simple socket TCP communication PHP implementation
Overview of network protocols
1. Physical layer: As the name implies, it is the existence of physical entities at the bottom of osi. All layers are based on his data, converting the binary in the computer into a transmission signal on the physical medium.
2. Data link layer: It handles the signals in the local network. LAN, Ethernet, WiFi, etc. are all defined in this layer. His function is to establish a data link link between communicating entities based on the services provided by the physical layer, and to transmit data packets in units of "frames". The frame contains headers and data. In addition, there is also the MAC-related knowledge we are familiar with, just post the link to understand it: Introduction to MAC address in the encyclopedia
3. Network layer: When it comes to network layer, we will understand an ip address problem that we have heard many times before: Also go directly to the link to understand: Regarding the IP address in the encyclopedia, the role of the network layer is to conduct cross-local network information exchange based on the data link layer to solve the local network communication. Network layer introduction
4. Transport layer: The above layers solve the connection between devices through MAC and IP, then the process in the network device is done through the transport layer. The transmission is end-to-end or host-to-host transmission. In Linux, host to port is called a socket (socket). Among them appeared the famous TCP/UDP protocol. Common well-known ports For
detailed TCP/UDP, we will also find a reference for a big guy. Refer to network programming TCP/IP and UDP and HTTP protocol
5. Application layer: It is to interpret and process the data obtained by the above protocol.