HTTP diagram-Understanding Web and network Fundamentals

1. Network-based TCP/IP

The network that is commonly used is run on the basis of the TCP/IP protocol family, and HTTP belongs to a subset within it.

The TCP/IP protocol family is divided into layers: application layer, Transport layer, network layer and data link layer respectively. The benefit of layering is that each level of change does not affect the overall effect.

Application Layer

The application layer determines the activities that communicate with the user when the application service is provided, such as FTP (file Transfer protocl, Files Transfer Protocol), DNS (Domain Name System, nameservers), and HTTP protocols.

Transport Layer

The transport layer provides data transfer between two computers in a network connection to the upper application layer, such as TCP (transmission Control Protocol, Transmission Protocol), UDP (user data Protocol, Subscriber Datagram Protocol), etc.

Network layer (Network interconnect layer)

The network layer is used to process packets flowing over the network

Link Layer

The hardware part that is used to process the connected network.

TCP/IP Communication transport Stream

Send end between layer and layer transfer data is, each layer must be hit on the layer exclusive header information, on the other hand, the receiving end in the layer and layer transfer data between layers will be removed from the corresponding layer of the header information.

2. About TCP, IP, and DNS

Ip

TCP is located in the transport layer to provide a reliable byte stream service, in order to ensure that the data transmission TCP protocol using three-time handshake policy

DNS is at the service level providing parsing services between domain names to IP

3. The relationship between the protocols and the HTTP protocol

4.uri and URLs

Uri (Uniform Resource Identifier, Uniform Resource Identifier): Identifies a unique Internet resource with a string, example of a URI:

Format of URI:

To specify the protocol type when accessing resources using http: or https: protocol scheme name

URL (Uniform Resource Locator, Uniform Resource Locator): Indicates where the internet is located

HTTP diagram-Understanding Web and network Fundamentals