History of TCP/IP

The beginning of the RFC(Request for Comments) format happened back in 1969 as part of the ARPANET(Advanced Research Projects Agency Network) project. RFC is the official channel for publication of the IETF, which stands for Internet Engineering Task Force. IETF is the IAB that stands for Internet Architecture Board; it is the general global community of computer network researchers.

History of TCP/IP

The work on TCP and IP dates back to the 1970s.  Vinton Cerf and Robert Kahn submitted the first-ever paper on the internet, titled “A Protocol for Packet Network Intercommunication.” at the IEEE Transactions on Communications conference in 1974. Later that year, an RFC was published (RFC 675), “Specification of Internet Transmission Control Program” by Vinton Cerf, Yogen Dalal, and Carl Sunshine in December 1974. The initial RFC 675 was not fully functional in 1974, so the authors were asked to revise the original work. They revised it several times, and finally, in 1981, the ‘v4’ specification of TCP/IP was published. This time it was not one but two separate RFCs:

• RFC 791 “Internet Protocol”
• RFC 793 “Transmission Control Protocol”

The ‘v4’ in IPv4 is a heritage of its relationship to TCP: no standalone IPv1, IPv2, or IPv3 protocols exist. Thus, ‘v4’ in IPv4 stands for the 4th version of the original RFC ever published on the internet. Thus, Vinton Cerf, Yogen Dalal, and Robert Kahn are known as the father of the internet. Yogen Dalal is an Indian who graduated from IIT Bombay.

The work on “Internet Protocol next generation (IPng)” started in 1994. IPng stands for IP next generation, but it was named IPv6 (the official name of Internet Protocoling) due to naming convention. Both TCP and IP have gone through significant updates in the last five decades. 100+ variants of TCP have been proposed in the literature to date. 10+ variants of TCP are available in the Linux Kernel (CUBIC TCP is the default). macOS has used CUBIC as default since 2014, and Microsoft Windows has used it as default since 2017.

Several new features were added to IP, such as Mobile IP and IP Security (IPSec).

Evolution of TCP:

Evolution of TCP 

RFC 793:

It was the first paper about the Internet and TCP. It included all features except congestion control. It was included from the next variant onwards. At that time, it was not known that the internet would become so much popular and advanced in the coming decades. The TCP header faced many challenges in the future. So, the option field was included in the TCP header for future optimizations.

TCP Tahoe was the first TCP variant with an in-built congestion control algorithm. It had its limitations, then TCP Reno came up with a solution, and so on.

TCP NewReno dominated the internet world for ten years; it is the default TCP in macOS now; TCP CUBIC has ruled the world for the last 15 years.

Earlier Status of Model: Initially, TCP didn’t even stand for what it stands now. It was originally a Transmission control program. It was designed to communicate between two distant computers by sending the data in the form of packets. TCP became the standard internet protocol for communication. The inventor’s goal was a reliable network between two computers that could ensure packet delivery safely, unlike UDP. 

Current Status of Model: Today internet uses both TCP and IP protocols for different purposes to achieve one common goal. IP is the network-level protocol while TCP is the transport-level protocol w.r.t to OSI(Open Systems Interconnection) five-layer model. TCP is an upper-layer protocol. IP adds the packet’s destination address where it will go to the receiver end. TCP establishes the secure and reliable connection between two communicating nodes and does its job of transferring data from the sender’s side and receiving it at the receiver’s end. TCP is bidirectional and capable of sending and receiving packets simultaneously.