Transmission Control Protocol/Inter

Transmission Control Protocol/Internetworking Protocol (TCP/IP)
Cerf and Kahn’s landmark 1973 paper outlined the protocols to achieve end-to-end
delivery of data. This was a new version of NCP. This paper on transmission control
protocol (TCP) included concepts such as encapsulation, the datagram, and the functions
of a gateway. A radical idea was the transfer of responsibility for error correction
from the IMP to the host machine. This ARPA Internet now became the focus of the
communication effort. Around this time responsibility for the ARPANET was handed
over to the Defense Communication Agency (DCA).
In October 1977, an internet consisting of three different networks (ARPANET,
packet radio, and packet satellite) was successfully demonstrated. Communication
between networks was now possible.
Shortly thereafter, authorities made a decision to split TCP into two protocols:
Transmission Control Protocol (TCP) and Internet Protocol (IP). IP would handle
datagram routing while TCP would be responsible for higher level functions such as
segmentation, reassembly, and error detection. The new combination became known as
TCP/IP.
In 1981, under a DARPA contract, UC Berkeley modified the UNIX operating
system to include TCP/IP. This inclusion of network software along with a popular operating
system did much for the popularity of networking. The open (non-manufacturerspecific)
implementation on Berkeley UNIX gave every manufacturer a working code
base on which they could build their products.
In 1983, authorities abolished the original ARPANET protocols, and TCP/IP
became the official protocol for the ARPANET. Those who wanted to use the Internet
to access a computer on a different network had to be running TCP/IP.