❑ NAT(Network Address Translation) : This is s a technique that maps public IP addresses with private IP addresses. It is mainly used to economize the number of IP addresses.
❑ Static NAT(=Basic NAT) : It is 1:1 mapping of private and public IP addresses.
❍ NAT is performed on a packet-by-packet basis.
❑ Dynamic NAT : It is M:N mapping of private and public IP addresses.
❍ The network connection of the terminal is available as many as the number of public IP addresses held.
* If there are 10 terminals and 4 public IP addresses, only 4 among 10 terminals can access the network.
❍ The terminal is assigned a public IP address available when accessing the network.
❍ The assigned public IP address is returned after a certain period of time after the network connection is terminated.
❑ PAT(Port Address Translation) : It is N:1 mapping of private and public IP addresses.
❍ The private IP address is identified by public IP address with the port number.