Nowadays, many people will be used internet that for their work, communication, education, economic and organization necessary that is used today. Network address translation (NAT) is a method of remapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device. A network is a system of hardware and software, put together for the purpose of communication and resource sharing. A network includes transmission hardware devise to interconnect transmission media and to control transmissions and software to decode and format data. The Internet protocol suite is the computer networking model and set of communications protocols used on the Internet and similar computer networks. Knowledge on how the internet is able to communicate with internet users is a mystery to some people. Internet communication need to be TCP/IP protocol which means that TCP is Transmission Control Protocol, or what is sometimes simply used to refer to Internet Protocol, is the basic unit for communication on the internet. This can also be applied to private internet, like Ethernet and so on. Despite TCP and IP being used interchangeably, there is a slight difference between the two in relation to the roles they play IP is directly responsible for obtaining internet addresses and then it is the work of TCP to deliver the data obtained to the addresses achieved by IP. TCP/IP provides end-to-end connectivity specifying how data should be packetized, addressed, transmitted, routed and received at the destination. This paper aim is described operation and models of TCP-IP suite in data communication network.