http--Study notes (1)

Noun Explanation:

Agreement:

Http:hypertext Transfer Protocol, Hypertext Transfer Protocol, protocol belonging to the application layer

Ftp:file Transfer Protocol, File Transfer Protocol, compared to the HTTP protocol more complex, control file two-way transmission, such as: Upload, download the use of this Protocol

IP protocol: Internet Protocol, Internetwork protocol, located at the network layer. The role is to send various packets to each other, to ensure that the transmission to the other side need to meet two important conditions, IP address and MAC address (Media Access Control)

Arp:address Resolution Protocol, a protocol used to resolve addresses, can be traced back to the corresponding MAC address according to the IP address of the communication party

Tcp:transmission Control Protocol, transmission protocol, sends the application layer to the transport layer of data flow, TCP divides the data stream into the appropriate length of the message segment

Udp:user data Protocol, User Datagram Protocol, unreliable datagram protocol, for the network layer above and the application layer below the interface, it once the application sent to the network layer of data sent out will not save data backup, so it is unreliable.

Uri:uniform Resource Identifier, Uniform Resource Identifier

Url:uniform Resource Locator, a Uniform Resource Locator, is the Web page address you need to enter when you use your browser to access Web pages

The difference between a URI and a URL: A URI is a purely syntactic structure that specifies different parts of a string that identifies a Web resource. A URL is a special case of a URI that contains enough information to locate a Web resource

Rfc:request for Comments, the request for a revised opinion, used to develop the HTTP protocol technical standards of the document, can be regarded as the Internet design documents, if not performed in accordance with the RFC standards may result in the inability to communicate

Router: router, is connected to the Internet in each LAN, WAN equipment, it will automatically select and set the route according to the situation of the channel, the best path, in order to send the signal. Routers are hubs of the Internet

Routing: When the IP protocol sends the data, it is routed through routing, which is explained in detail below

IP Address: The address to which the node is assigned, corresponding to the domain name

MAC address: The fixed address that the network card belongs to, usually a PC corresponding to a MAC address, and no longer change

Dns:domain Name System, domain name systems, a distributed database that maps domain names and IP addresses on the Internet, makes it easier for users to access the Internet without remembering the number of IP strings that can be read directly by the machine. For example: www.baidu.com corresponding IP is 183.232.231.173, in the address bar input both content can access to Baidu page, domain name is www.baidu.com, user-friendly memory

TCP/IP protocol family:

Different hardware, the communication between the operating system, all of this requires a rule, from the cable specifications to the choice of IP address method, the method of looking for an offsite user, the sequence of communication between the two sides, and the Web page display needs to process the steps, and so on. In this way, the protocol associated with the Internet is collectively called TCP/IP, which is the general term of the protocol family used in the IP protocol communication process.

Layered management of TCP/IP

Application layer: Decides to provide the user with the application service communication activity, the TCP/IP protocol family has stored various kinds of common application services. FTP and DNS services, for example, are two of these.

Transport Layer: The transport layer to the upper application layer, provides data transmission between two computers in the network connection, and two different protocols in the transport layer, TCP and UDP

Network layer (Network interconnect layer): Used to process packets that flow over the network. A packet is the smallest unit of data transmitted over a network. This layer specifies what path (the so-called transmission route) arrives at the opponent's computer and transmits the packet to the other. When transferring from one computer or network device to another, the role of the network layer is to select a transmission route within a wide range of options, IP protocol

Link layer (Data Link layer, network interface layer): Used to process the hardware part of the network connected. This includes control of the operating system, device drivers for hardware, NIC (Network Interface card, LAN adapter, NIC), and physical visible parts such as fiber optics (including all transmission media such as connectors). The hardware category is within the scope of the link layer.

When sending information:

(sender side) application Layer---Transport layer--network layer-to-link layer (Add Communication destination address (MAC address))

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(Receive side) Link layer--network layer---Transport layer--link layer

When transmitting data between layer and layer, each layer will be hit with the header information of the layer, and when the layer and layer of the receiving end transmits the data, the corresponding header will be removed after each layer. Package

Note: Some books have a session layer in between the application layer and the Transport layer

IP protocol belongs to the network layer in the transmission of information need to go through routing, no matter which computer, which network equipment can not fully grasp the details of the Internet, the sending side using the ARP protocol resolution found that the unresolved success will be sent to a MAC address of the router, The router then resolves to the next router until it is finally sent to the correct address

The TCP protocol belongs to the transport layer, provides a reliable byte stream service, the chunk data is divided into packet segment for the management of packets, the reason is that TCP "reliable" because the TCP protocol used in the "three-time handshake" policy

The sending side sends a packet with a SYN ID to the other party, and the receiving end receives a packet with the Syn/ack ID to tell the sender that it has received it, and sends a packet with an ACK ID on it, representing the end of the handshake.

The specific process of sending data to the receiving end of the sender:

URI format:

Not case-sensitive, you can also use data: or JavaScript: This class specifies the schema name of the data or script

The server address can be a DNS resolvable name, or an IPV4 address name (192.168.1.1), or a IPV6 address name ([0:0:0:0:0:0:0:1])

Server port number, optional, default port number is omitted

A hierarchical file path refers to the path of the file on the server

Query string, as an option

Fragment identifier, in a location on the page, an option

http--Study notes (1)