- computer network architecture
Computer network architecture:
1. A collection of layers and the protocol of computer network,
(2) is a computer network system structure and its components should be completed by the function of accurate definition,
3. The implementation is to follow the premise of architecture with what kind of hardware or software to complete these functions,
4. Architecture is abstract, and the implementation is concrete, is the real running on the computer hardware and software,
The OSI architecture:
1. Only defines the framework, there is no set each layer of the specific agreement;
2. The power of the OSI reference model is the model itself;
TCP/IP protocol architecture:
1. The model itself is not much use;
2. The strength of the TCP/IP reference model embodied in the agreement;
Five layer protocol architecture:
Application layer:
Task: (1) through the application process is the interaction between complete specific network applications. Application layer protocol defines the inter-process communication and interaction on the basis of the
(2) protocol: HTTP, DNS, SMPT, pop3...
(3) to send data unit: a message
Transport layer:
Task: (1) for communication between the application process provides a common transport services; End-to-end transmission; Reuse and points in function, and support multiple process
(2) protocol: TCP, udp
(3) to send data unit: a message (TCP) and user datagram (udp)
Transport layer:
(1) mission: to realize the communication between different host; Select the appropriate routing; Host-to-host transport
(2) agreement: IP, rip, ospf
(3) to send data unit: a datagram
The data link layer:
Task: (1) to transmit data frames from one node to the adjacent node; Realizing the data transmission between adjacent nodes; Flow control, error handling; Adjacent nodes
(2) agreement: the Ethernet protocol, wifi
(3) to send data unit: frame
The physical layer:
(1) mission: to realize the binary bit stream transmission process, will be a one bit of data frames transmitted from one node to the adjacent node; Implementation of binary bit stream and the signal conversion between process, complete signal transmission process; What electronic signals to represent 1, 0, involving mechanical, electronic and other interface, as well as the physical network transmission medium under
(2) agreement: has nothing to do with the link, has many physical Ethernet protocols, such as: copper, twisted-pair cable, optical fiber, etc.
(3) to send data unit: bit
The OSI model:
The session layer:
(1) function is used to manage process of conversation between two processes;
(2), for example: breakpoint continuingly, unified operation on both sides at the same time;
The presentation layer:
(1) unified communications between the syntax and semantic of passing information;
(2) the Big endian, Little endian
(3) the RPC, web service, how to transfer an integer;
(4) such as: is the data compression, compression way;
The architecture of TCP/IP
Network interface layer:
(1) to IP packet encapsulation into suitable for transmission through the network frame format;
(2) of the different types of networks with different network interface layer, with the corresponding network interface protocol
The layer:
(1) to realize the connection between the two terminals of different types of Internet communication process,




Note:
(1) : the physical object is a binary bit stream;
(2) data link layer: the corresponding frame processing object is specific transmission network;
(3) the layer: the processing object is IP packet,