1984 Nian OSI Interconnection seven-layer model for open systems ----> network industry laws and regulations ----> ISO International Organization for Standardization promulgated
Effect of PDUs (protocol data units)
Application Layer ----> interface between the application and the user, the network ----> Data
Presentation layer ----> data format representation ----> Data
Session layer ----> establish and maintain a session ----> Data
Transport Layer ----> difference port number ----> data segment
Layer network down ----> the IP address, path preferred ---> Packet
The data link layer ----> MAC address addressing , error checking. ----> data frame
The physical layer ----> establishing and maintaining physical connections - --->bitstream
1969 Nian TCP / IP five-layer reference model ----> US Defense Advanced Research Projects Agency in the study ARPANET when asked the TCP / IP reference model
Application Layer ----> the TFTP , the HTTP , the SNMP , the FTP , the SMTP , the DNS , the Telnet
Transport Layer ----> the TCP , the UDP
The network layer ----> IP , ICMP , OSPF , BGP , ARP , RARP
The data link layer ----> the SLIP , CSLIP , the PPP , the MTU
The physical layer ----> an IEEE 802 , the IEEE802.2
Stratified reason: each division of specific, targeted troubleshooting.
Data encapsulation and decapsulation process:
Package: by a machine A begins application-layer data encapsulation, the encapsulating layer after each layer is present in the message packet header. Eventually to the application layer 01 for transmission.
Decapsulation: the physical layer through the transport, the machine B in the physical layer of the lower layer decapsulates, after each layer when the layer is put to open packet header.
