Comparison of TCP / IP and the OSI model: OSL model TCP / IP model
Application layer
Presentation Layer - "Application Layer
Session Layer
The transport layer - "Transport Layer
Network layer - "Network Layer
The data link layer - "Network Interface Layer
Physical Layer
TCP / IP application layer protocol hierarchy :() TLELNE FTP SMTP DNS TFTP
(Transport Layer) T C P U D P
(Network layer) ICMP IP ARP RARP
(Network interface layer) Network Interface Layer
TCP / IP protocol functions: 1 split upper application
2. Establish a connection from end to end
3. The data segments transferred from one host to another host
4. The reliability of the data transmission section
User Datagram Protocol UDP: UDP packet does not guarantee the reliability and sequence fields, field flow control, poor reliability
Problems: The method of network congestion: threshold value of 8 is reduced to half of the timeout, and then increase addition
network timeout